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  • CLASSES

    Alpha-Blockers

    DEA CLASS

    Rx

    DESCRIPTION

    Oral alpha-1 adrenergic blocker
    Used to treat benign prostatic hypertrophy (BPH) in adult males
    Similar to tamsulosin, alfuzosin appears to be more specific for alpha-1a receptors than other alpha-blockers

    COMMON BRAND NAMES

    Uroxatral

    HOW SUPPLIED

    Alfuzosin/Uroxatral Oral Tab ER: 10mg

    DOSAGE & INDICATIONS

    For the symptomatic treatment of benign prostatic hyperplasia (BPH).
    Oral dosage
    Adult males

    10 mg PO once daily with food, with the same meal each day.

    For the treatment of erectile dysfunction (ED)† in combination with sildenafil in patients with lower urinary tract symptoms (LUTS) suggestive of BPH.
    Oral dosage
    Adult males

    10 mg PO once daily with food, with the same meal each day. In a pilot study, sildenafil (25 mg PO once daily at night) combined with alfuzosin (10 mg PO once daily) proved to be more effective than monotherapy with either agent for improving both voiding and sexual function in men with ED and LUTS suggestive of benign prostatic hyperplasia (BPH). Marked improvements in International Prostate Symptom Scores (IPSS) were noted with the combination compared to each agent alone. As expected, alfuzosin monotherapy significantly improved urinary frequency, nocturia, maximum urinary flow rate (Qmax), and postvoid residual urine (PVRU) volume whereas sildenafil showed minimal or no significant impact. Monotherapy with sildenafil showed significant improvements in erectile function whereas alfuzosin showed only a trend for improvement. The combination of sildenafil and alfuzosin, however, showed the most improvement in LUTS and erectile function compared to monotherapy with each agent.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    10 mg/day PO.

    Geriatric

    10 mg/day PO.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    Infants

    Not indicated.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Mild hepatic impairment (Child-Pugh class A): No dosage adjustment needed; use with caution.
    Moderate or severe hepatic impairment (Childs-Pugh class B or C): Do not use.

    Renal Impairment

    CrCl 30 mL/minute and greater: No dosage adjustment needed.
    CrCl less than 30 mL/minute: Limited safety data are available; therefore, administer alfuzosin with caution due to the potential for increased alfuzosin exposure.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Extended-release tablets:
    Swallow whole. Patients should not crush, cut or chew the extended-release tablets.
    Administer orally immediately after the same meal each day. Take with food. Do not take on an empty stomach.

    STORAGE

    Uroxatral:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Alfuzosin is contraindicated in patients with known hypersensitivity to alfuzosin, such as urticaria and angioedema, or to any component of the commercial product.

    Hepatic disease

    Although the pharmacokinetics of alfuzosin have not been studied in patients with mild hepatic impairment, caution should be exercised when using the drug in such patients as blood concentrations of alfuzosin may be increased. Alfuzosin is contraindicated in patients with moderate or severe hepatic disease (Childs-Pugh classes B and C) because alfuzosin blood concentrations are increased in these patients. Similarly, alfuzosin use with potent CYP3A4 inhibitors is also contraindicated, since alfuzosin blood levels are increased.

    Angina, coronary artery disease, hypotension, orthostatic hypotension, syncope

    Orthostatic hypotension with or without symptoms (e.g., dizziness) may develop within a few hours following administration of alfuzosin. As with other alpha-blockers, there is a potential for syncope. Patients should be warned of the possible occurrence of such events and should avoid situations where injury could result should syncope occur. There may be an increased risk of hypotension and/or postural hypotension and syncope when taking alfuzosin during concomitant therapy with anti-hypertensive medication and/or nitrates. Alfuzosin should be discontinued if angina occurs or if it recurs or worsens in patients who are receiving therapy for coronary artery disease.

    Apheresis, AV block, bradycardia, cardiomyopathy, celiac disease, females, fever, heart failure, human immunodeficiency virus (HIV) infection, hyperparathyroidism, hypocalcemia, hypokalemia, hypomagnesemia, hypothermia, hypothyroidism, long QT syndrome, myocardial infarction, pheochromocytoma, QT prolongation, rheumatoid arthritis, sickle cell disease, sleep deprivation, stroke, systemic lupus erythematosus (SLE)

    Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with a dose of alfuzosin 10 mg than with a dose of 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. Use alfuzosin with caution in patients with conditions that may increase the risk of QT prolongation including congenital long QT syndrome, bradycardia, AV block, heart failure, stress-related cardiomyopathy, myocardial infarction, stroke, hypomagnesemia, hypokalemia, hypocalcemia, or in patients receiving medications known to prolong the QT interval or cause electrolyte imbalances. Females, people 65 years and older, patients with sleep deprivation, pheochromocytoma, sickle cell disease, hypothyroidism, hyperparathyroidism, hypothermia, systemic inflammation (e.g., human immunodeficiency virus (HIV) infection, fever, and some autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus (SLE), and celiac disease) and patients undergoing apheresis procedures (e.g., plasmapheresis [plasma exchange], cytapheresis) may also be at increased risk for QT prolongation.   

    Renal failure, renal impairment

    Alfuzosin should be used cautiously in patients with severe renal disease (CrCl less than 30 mL/minute) including renal failure because limited safety data are available. Safety data in patients with mild to moderate renal impairment during clinical trials was similar to patients with normal renal function.

    Prostate cancer

    Prostate cancer and benign prostatic hyperplasia (BPH) cause many of the same symptoms. These two diseases frequently coexist. Therefore, patients thought to have BPH should be examined to rule out the presence of prostate cancer prior to starting treatment with alfuzosin.

    Surgery

    Alfuzosin should generally be used with caution in patients who will undergo general surgery; additive hypotension under general anesthesia may occur in rare instances with selective alpha blocker treatment.

    Ocular surgery

    Patients receiving or who have previously received treatment with alfuzosin or other alpha-1 blockers may be at risk for intraoperative floppy iris syndrome (IFIS) during surgery for cataracts (ocular surgery). Intraoperative floppy iris syndrome is a small pupil syndrome variant that is characterized by a flaccid iris that billows in response to intraoperative irrigation currents, progressive intraoperative miosis despite preoperative dilation with standard mydriatic drugs, and potential prolapse of the iris toward the phacoemulsification incisions. The ophthalmologist should be prepared for possible modifications to their surgical technique such as the use of iris hooks, iris dilator rings, or viscoelastic substances. There does not appear to be a benefit of stopping alpha blocker therapy prior to cataract surgery.

    Priapism

    Rarely (probably less than 1 in 50,000), alfuzosin, like other alpha adrenergic blockers, has been associated with priapism (persistent painful penile erection unrelated to sexual activity). Priapism, if not treated promptly, can result in irreversible damage to the erectile tissue. Because this condition can lead to permanent impotence if not properly treated, patients should be advised about the seriousness of the condition. Males who have an erection lasting greater than 4 hours, whether painful or not, should seek emergency medical attention.

    Geriatric

    Geriatric patients should be monitored carefully for exaggerated hypotensive effects (e.g., first-dose effect) to alfuzosin. However, in clinical studies, no overall differences in safety or effectiveness were observed between elderly (65 years of age and older) and younger subjects. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to the OBRA guidelines, assessment of the underlying causes and identification of the type/category of urinary incontinence needs to be documented prior to or soon after the time of initiating treatment with a urinary incontinence medication. Alpha-blockers are not commonly used for urinary incontinence. These medications have specific and limited indications based on the cause and categorization of incontinence. Patients should be assessed periodically for medication effects on urinary incontinence as well as lower urinary tract symptoms and treatment tolerability.

    Pregnancy

    Alfuzosin is not indicated for use in females; therefore, no adequate well-controlled studies in pregnant women have been done to assess the safety of alfuzosin use during pregnancy. Alfuzosin was not teratogenic, embryotoxic or fetotoxic in rats at plasma exposure levels (based on AUC of unbound drug) up to 1,200-times the maximum recommended human dose (MRHD) of 10 mg/day. In rabbits administered up to 3-times the MRHD (based on body surface area) no embryofetal toxicity or teratogenicity was observed. Gestation was slightly prolonged in rats at exposure levels approximately 12-times the MRHD, but difficulties with parturition were not observed.

    Breast-feeding

    There is no known use of alfuzosin in breast-feeding mothers; it is not known whether alfuzosin distributes into breast milk.

    Children, infants

    Alfuzosin is only used to treat benign prostatic hyperplasia in men. It is not indicated for use in pediatric patients, and has not been studied in infants and children less than 2 years of age. The drug has been studied in pediatric patients 2 years and older but has not been proven effective. Efficacy of alfuzosin was not demonstrated in a randomized, double-blind, placebo-controlled, efficacy and safety trial conducted in 172 children and adolescents 2 to 16 years of age with elevated detrusor leak point pressure (LPP of 40 cm H2O or more) of neurologic origin treated with alfuzosin using pediatric formulations. The trial included a 12-week efficacy phase followed by a 40-week safety extension period. No statistically significant difference in the proportion of patients achieving a detrusor LPP of less than 40 cm H20 was observed between the alfuzosin and placebo groups. During the trial, the adverse reactions reported in 2% or more of alfuzosin-treated pediatric patients and at a higher incidence than in the placebo group were: pyrexia, headache, respiratory tract infection, cough, epistaxis and diarrhea. The adverse reactions reported for the whole 12-month trial period, which included the open-label extension, were similar in type and frequency to the reactions observed during the 12-week period.

    ADVERSE REACTIONS

    Severe

    atrial fibrillation / Early / Incidence not known
    bradycardia / Rapid / Incidence not known
    myocardial infarction / Delayed / Incidence not known
    angioedema / Rapid / Incidence not known
    toxic epidermal necrolysis / Delayed / Incidence not known

    Moderate

    impotence (erectile dysfunction) / Delayed / 1.0-2.0
    constipation / Delayed / 1.0-2.0
    priapism / Early / 0-1.0
    ejaculation dysfunction / Delayed / 0-1.0
    orthostatic hypotension / Delayed / 0.4-0.6
    hypotension / Rapid / 0.4-0.4
    confusion / Early / Incidence not known
    sinus tachycardia / Rapid / Incidence not known
    edema / Delayed / Incidence not known
    chest pain (unspecified) / Early / Incidence not known
    angina / Early / Incidence not known
    gastritis / Delayed / Incidence not known
    erythema / Early / Incidence not known
    jaundice / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known
    hepatitis / Delayed / Incidence not known
    QT prolongation / Rapid / Incidence not known
    floppy iris syndrome / Delayed / Incidence not known
    thrombocytopenia / Delayed / Incidence not known

    Mild

    dizziness / Early / 5.7-5.7
    headache / Early / 3.0-3.0
    infection / Delayed / 2.0-3.0
    fatigue / Early / 2.7-2.7
    pharyngitis / Delayed / 1.0-2.0
    sinusitis / Delayed / 1.0-2.0
    dyspepsia / Early / 1.0-2.0
    abdominal pain / Early / 1.0-2.0
    nausea / Early / 1.0-2.0
    asthenia / Delayed / 0-1.0
    insomnia / Early / 0-1.0
    diaphoresis / Early / 0-1.0
    drowsiness / Early / 0-1.0
    rash / Early / 0-1.0
    pruritus / Rapid / 0-1.0
    urticaria / Rapid / 0-1.0
    syncope / Early / 0.2-0.2
    vertigo / Early / Incidence not known
    rhinitis / Early / Incidence not known
    diarrhea / Early / Incidence not known
    vomiting / Early / Incidence not known
    flushing / Rapid / Incidence not known

    DRUG INTERACTIONS

    Abarelix: (Major) Since abarelix can cause QT prolongation, abarelix should be used cautiously with other drugs that are associated with QT prolongation, such as alfuzosin.
    Acebutolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Alpha-blockers: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Ambrisentan: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensives, such as ambrisentan, has the potential to cause hypotension in some patients.
    Amiodarone: (Major) The concomitant use of amiodarone and other drugs known to prolong the QT interval should only be done after careful assessment of risks versus benefits. Amiodarone, a Class III antiarrhythmic agent, is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Although the frequency of TdP is less with amiodarone than with other Class III agents, amiodarone is still associated with a risk of TdP. Due to the extremely long half-life of amiodarone, a drug interaction is possible for days to weeks after discontinuation of amiodarone. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. In addition, alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes and amiodarone is a CYP3A4 inhibitor. Concurrent use may increase systemic exposure to alfuzosin and further increase the risk for QT prolongation.
    Amisulpride: (Major) Monitor the ECG in patients taking amisulpride with alfuzosin due to the risk of additive QT prolongation. Amisulpride causes dose- and concentration- dependent QT prolongation.
    Amoxicillin; Clarithromycin; Omeprazole: (Contraindicated) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Amprenavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Amyl Nitrite: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Anagrelide: (Major) Torsades de pointes (TdP) and ventricular tachycardia have been reported during post-marketing use of anagrelide. A cardiovascular examination, including an ECG, should be obtained in all patients prior to initiating anagrelide therapy. Monitor patients during anagrelide therapy for cardiovascular effects and evaluate as necessary. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with anagrelide include alfuzosin.
    Apomorphine: (Moderate) Use apomorphine and alfuzosin together with caution due to the risk of additive QT prolongation. Dose-related QTc prolongation is associated with therapeutic apomorphine exposure. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Aprepitant, Fosaprepitant: (Moderate) Increased alfuzosin exposure may occur with multi-day regimens of oral aprepitant, resulting in increased alfuzosin-related adverse reactions, including QT prolongation. Alfuzosin is a CYP3A4 substrate and aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor. When administered as a single oral or single intravenous dose, the inhibitory effect of aprepitant on CYP3A4 is weak and did not result in a clinically significant increase in the AUC of a sensitive substrate.
    Aripiprazole: (Moderate) Use caution when administering alfuzosin with aripiprazole due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. QT prolongation has occurred during therapeutic use of aripiprazole and following overdose.
    Arsenic Trioxide: (Major) Arsenic trioxide administration is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Avoid the use of arsenic trioxide with other agents that may prolong the QT interval or increase the risk of torsades de pointes. If possible, drugs with potential to prolong the QT interval should be discontinued prior to beginning arsenic trioxide therapy. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. There have been no reports of torsades de pointes (TdP) in extensive post-marketing experience with alfuzosin outside the United States. There are no known pharmacokinetic/pharmacodynamic studies of the effect of other alpha-blockers on cardiac repolarization. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients with a known history of cardiac arrhythmias, QT prolongation (e.g., congenital or acquired QT prolongation), history of torsades de pointes, or patients who are taking medications known to prolong the QT interval.
    Artemether; Lumefantrine: (Major) Concurrent use of alfuzosin and artemether; lumefantrine should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Consider ECG monitoring alfuzosin must be used with or after artemether; lumefantrine treatment. Administration of artemether; lumefantrine is associated with prolongation of the QT interval. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. (Major) Concurrent use of alfuzosin and artemether; lumefantrine should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Consider ECG monitoring if alfuzosin must be used with or after artemether; lumefantrine treatment. Administration of artemether; lumefantrine is associated with prolongation of the QT interval. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Asenapine: (Major) Asenapine has been associated with QT prolongation. According to the manufacturer of asenapine, the drug should be avoided in combination with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Atazanavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Atazanavir; Cobicistat: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Atenolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Atenolol; Chlorthalidone: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Atomoxetine: (Moderate) Use caution when administering alfuzosin with atomoxetine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
    Avanafil: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on alfuzosin therapy before initiating therapy with avanafil at the lowest dose. Conversely, patients already receiving an optimized dose of avanafil should be started on the lowest dose of alfuzosin; increases in the alpha-blocker dose should be done in a stepwise fashion. Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of avanafil and alfuzosin.
    Azithromycin: (Major) Avoid coadministration of azithromycin with alfuzosin due to the increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. QT prolongation and torsade de pointes (TdP) have been spontaneously reported during azithromycin postmarketing surveillance. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Bedaquiline: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering bedaquiline with alfuzosin. Bedaquiline has been reported to prolong the QT interval. Prior to initiating bedaquiline, obtain serum electrolyte concentrations and a baseline ECG. An ECG should also be performed at least 2, 12, and 24 weeks after starting bedaquiline therapy. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Bendroflumethiazide; Nadolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Bepridil: (Contraindicated) Due to an increased risk of developing cardiac arrhythmias, avoid concomitant use of bepridil and alfuzosin. According to the manufacturer, bepridil is contraindicated for use with drugs that prolong the QT interval due to the risk of TdP, including antiarrhythmic agents which prolong the QT interval (e.g., Class IA antiarrhythmics and Class III antiarrhythmics) and tricyclic antidepressants. Bepridil inhibits the cardiac conduction system, and may slow conduction through the AV node, increasing the duration of the refractory period of the action potential. Bepridil administration has Class I antiarrhythmic properties and is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Patients receiving other drugs which have the potential for QT prolongation have an increased risk of developing proarrhythmias during bepridil therapy. In addition, based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. In a post-marketing study evaluating the effect of using alfuzosin with another drug with a comparable QT effect, an additive effect on the QT interval was observed but it was less than that observed with moxifloxacin alone. The study was not designed to make a direct statistical comparison between the drugs. There have been no reports of torsades de pointes (TdP) in extensive post-marketing experience with alfuzosin outside the United States. There are no known pharmacokinetic/pharmacodynamic studies of the effect of other alpha-blockers on cardiac repolarization. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients with a known history of cardiac arrhythmias, QT prolongation (e.g., congenital or acquired QT prolongation), history of torsades de pointes, or patients who are taking medications known to prolong the QT interval. In addition to avoiding concurrent drug interactions, the potential for TdP can be reduced by avoiding the use of QT prolonging drugs in patients at substantial risk for TdP. Examples of general risk factors for TdP include congenital long QT syndrome, female sex, elderly patients, significant bradycardia, hypokalemia, hypomagnesemia, and underlying cardiac disease (e.g., arrhythmias, cardiomyopathy, acute myocardial ischemia).
    Berotralstat: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with berotralstat. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A4 substrate and berotralstat is a moderate CYP3A4 inhibitor. Coadministration of another moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Beta-adrenergic blockers: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Betaxolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Concomitant use of metronidazole and alfuzosin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Concomitant use of metronidazole and alfuzosin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
    Bisoprolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Boceprevir: (Contraindicated) Concurrent use of alfuzosin and boceprevir is contraindicated due to the potential for serious/life-threatening reactions. Boceprevir is a potent inhibitor of CYP3A4, which is responsible for alfuzosin metabolism. Coadministration may result in large increases in alfuzosin serum concentrations, which could cause adverse events such as hypotension.
    Brimonidine; Timolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Buprenorphine: (Major) Buprenorphine should be used cautiously and with close monitoring with should be used cautiously and with alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Buprenorphine has been associated with QT prolongation and has a possible risk of torsade de pointes (TdP). FDA-approved labeling for some buprenorphine products recommend avoiding use with Class 1A and Class III antiarrhythmic medications while other labels recommend avoiding use with any drug that has the potential to prolong the QT interval.
    Buprenorphine; Naloxone: (Major) Buprenorphine should be used cautiously and with close monitoring with should be used cautiously and with alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Buprenorphine has been associated with QT prolongation and has a possible risk of torsade de pointes (TdP). FDA-approved labeling for some buprenorphine products recommend avoiding use with Class 1A and Class III antiarrhythmic medications while other labels recommend avoiding use with any drug that has the potential to prolong the QT interval.
    Cabotegravir; Rilpivirine: (Moderate) Caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Carteolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Carvedilol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Ceritinib: (Contraindicated) Alfuzosin is contraindicated for use with ceritinib due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ceritinib is a strong CYP3A4 inhibitor that also causes concentration-dependent QT prolongation. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Chloramphenicol: (Contraindicated) Alfuzosin is contraindicated for use with chloramphenicol due to the potential for serious/life-threatening reactions, including hypotension. Alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes; strong inhibitors of CYP3A4, such as chloramphenicol, block the metabolism of alfuzosin and increase systemic exposure to alfuzosin. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Chloroprocaine: (Major) Alfuzosin has a slight effect to prolong the QT interval, and should be used cautiously in combination with other medications known to prolong the QT interval, such as local anesthetics.
    Chloroquine: (Major) Avoid coadministration of chloroquine with alfuzosin due to the increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Chloroquine is associated with an increased risk of QT prolongation and torsade de pointes (TdP); the risk of QT prolongation is increased with higher chloroquine doses. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Chlorpromazine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and chlorpromazine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Chlorpromazine, a phenothiazine, is associated with an established risk of QT prolongation and TdP. Concurrent use may result in additive QT prolongation.
    Cimetidine: (Moderate) Alfuzosin is extensively metabolized by hepatic enzymes. Administration of of cimetidine, an inhibitor of hepatic cytochrome P450, with alfuzosin may increase the serum concentration of alfuzosin.
    Ciprofloxacin: (Moderate) Use caution when administering alfuzosin with ciprofloxacin due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Rare cases of QT prolongation and torsade de pointes (TdP) have been reported with ciprofloxacin during postmarketing surveillance.
    Cisapride: (Contraindicated) Coadministration of cisapride and alfuzosin is contraindicated due to the potential for QT prolongation and torsades de pointes (TdP). QT prolongation and ventricular arrhythmias, including TdP and death, have been reported with cisapride. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Citalopram: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), concurrent use of alfuzosin and citalopram should be avoided if possible. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Citalopram causes dose-dependent QT interval prolongation. According to its manufacturer, concurrent use of citalopram with other drugs that prolong the QT interval is not recommended. If concurrent therapy is considered essential, ECG monitoring is recommended.
    Clarithromycin: (Contraindicated) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Clofazimine: (Major) Monitor ECGs for QT prolongation when clofazimine is administered with alfuzosin. QT prolongation and torsade de pointes have been reported in patients receiving clofazimine in combination with QT prolonging medications. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Clozapine: (Moderate) Use caution when administering alfuzosin with clozapine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Treatment with clozapine has been associated with QT prolongation, torsade de pointes, cardiac arrest, and sudden death.
    Cobicistat: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Codeine; Phenylephrine; Promethazine: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Codeine; Promethazine: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Conivaptan: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with conivaptan. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A substrate; conivaptan is a moderate CYP3A inhibitor. Coadministration of another moderate CYP3A inhibitor increased the alfuzosin overall exposure by 1.3-fold.
    Crizotinib: (Major) Avoid coadministration of crizotinib with alfuzosin due to the risk of QT prolongation; increased alfuzosin exposure may also occur. If concomitant use is unavoidable, monitor ECGs for QT prolongation and monitor electrolytes; an interruption of therapy, dose reduction, or discontinuation of therapy may be necessary for crizotinib if QT prolongation occurs. Also monitor for evidence of alfuzosin-related adverse effects (e.g., hypotension). Alfuzosin is a CYP3A4 substrate that, based on electrophysiology studies performed by the manufacturer, may prolong the QT interval in a dose-dependent manner. Crizotinib is a moderate CYP3A inhibitor that has also been associated with concentration-dependent QT prolongation. Coadministration with a moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Darunavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Darunavir; Cobicistat: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Dasatinib: (Moderate) Use dasatinib with caution in combination with alfuzosin. In vitro studies have shown that dasatinib has the potential to prolong the QT interval. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Degarelix: (Moderate) Consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients receiving alfuzosin as concurrent use may increase the risk of QT prolongation. Androgen deprivation therapy (i.e., degarelix) may prolong the QT/QTc interval. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Delavirdine: (Contraindicated) Alfuzosin is contraindicated for use with delavirdine due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; delavirdine is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Desflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Deutetrabenazine: (Moderate) Use caution during coadministration of alfuzosin and deutetrabenazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Deutetrabenazine may prolong the QT interval, but the degree of QT prolongation is not clinically significant when deutetrabenazine is administered within the recommended dosage range.
    Dextromethorphan; Quinidine: (Major) Alfuzosin should be used cautiously with quinidine. Quinidine administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Diltiazem: (Major) Alfuzosin and diltiazem may have additive vasodilatory actions; concurrent use of these agents can result in hypotension. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. Diltiazem, a moderately potent CYP3A4 inhibitor, increases the Cmax and AUC of alfuzosin; alfuzosin increases both the Cmax and AUC of diltiazem, however, no changes in blood pressure are reported.
    Disopyramide: (Major) Alfuzosin should be used cautiously and with close monitoring with disopyramide. Disopyramide administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Dofetilide: (Major) Coadministration of dofetilide and alfuzosin is not recommended as concurrent use may increase the risk of QT prolongation. Dofetilide, a Class III antiarrhythmic agent, is associated with a well-established risk of QT prolongation and torsade de pointes (TdP). Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Dolasetron: (Moderate) Administer dolasetron with caution in combination with alfuzosin as concurrent use may increase the risk of QT prolongation. Dolasetron has been associated with a dose-dependent prolongation in the QT, PR, and QRS intervals on an electrocardiogram. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Dolutegravir; Rilpivirine: (Moderate) Caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Donepezil: (Moderate) Use donepezil with caution in combination with alfuzosin due to the potential for QT prolongation. Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Donepezil; Memantine: (Moderate) Use donepezil with caution in combination with alfuzosin due to the potential for QT prolongation. Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Dorzolamide; Timolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Doxazosin: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Dronedarone: (Contraindicated) Concurrent use of dronedarone and alfuzosin is contraindicated. Dronedarone administration is associated with a dose-related increase in the QTc interval. The increase in QTc is approximately 10 milliseconds at doses of 400 mg twice daily (the FDA-approved dose) and up to 25 milliseconds at doses of 1600 mg twice daily. Although there are no studies examining the effects of dronedarone in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation. The concomitant use of dronedarone with other drugs that prolong the QTc may induce Torsade de Pointes (TdP) and is contraindicated. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Droperidol: (Major) Droperidol should be administered with extreme caution to patients receiving other agents that may prolong the QT interval. Droperidol administration is associated with an established risk for QT prolongation and torsades de pointes (TdP). Any drug known to have potential to prolong the QT interval should not be coadministered with droperidol. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with droperidol include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Duvelisib: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with duvelisib. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A4 substrate. duvelisib is a moderate CYP3A4 inhibitor. Coadministration of another moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Efavirenz: (Moderate) Consider alternatives to efavirenz when coadministering with alfuzosin as concurrent use may increase the risk of QT prolongation. QTc prolongation has been observed with the use of efavirenz. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Efavirenz; Emtricitabine; Tenofovir: (Moderate) Consider alternatives to efavirenz when coadministering with alfuzosin as concurrent use may increase the risk of QT prolongation. QTc prolongation has been observed with the use of efavirenz. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Consider alternatives to efavirenz when coadministering with alfuzosin as concurrent use may increase the risk of QT prolongation. QTc prolongation has been observed with the use of efavirenz. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Elbasvir; Grazoprevir: (Moderate) Administering alfuzosin with elbasvir; grazoprevir may result in elevated alfuzosin plasma concentrations. Alfuzosin is a substrate of CYP3A; grazoprevir is a weak CYP3A inhibitor. If these drugs are used together, closely monitor for signs of adverse events.
    Eliglustat: (Moderate) Use caution when administering alfuzosin with eliglustat due to the potential for QT prolongation. Alfuzosin may prlong the QT interval in a dose-dependent manner. Additionally, eliglustat is predicted to cause PR, QRS, and/or QT prlongation at significantly elevated plasma concentrations.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Moderate) Caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: (Moderate) Caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Enalapril; Felodipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Encorafenib: (Major) Avoid coadministration of encorafenib and alfuzosin due to QT prolongation. If concurrent use cannot be avoided, monitor ECGs for QT prolongation and monitor electrolytes; correct hypokalemia and hypomagnesemia prior to treatment. Encorafenib is associated with dose-dependent prolongation of the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Enflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Entrectinib: (Major) Avoid coadministration of entrectinib with alfuzosin due to the risk of QT prolongation. Entrectinib has been associated with QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Eribulin: (Major) Eribulin has been associated with QT prolongation. If eribulin and another drug that prolongs the QT interval, such as alfuzosin, must be coadministered, ECG monitoring is recommended; closely monitor the patient for QT interval prolongation.
    Erythromycin: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and erythromycin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Erythromycin administration is associated with QT prolongation and TdP. In addition, coadministration of erythromycin, a CYP3A4 inhibitor, with alfuzosin, a CYP3A4 substrate, may result in elevated alfuzosin plasma concentrations.
    Erythromycin; Sulfisoxazole: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and erythromycin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Erythromycin administration is associated with QT prolongation and TdP. In addition, coadministration of erythromycin, a CYP3A4 inhibitor, with alfuzosin, a CYP3A4 substrate, may result in elevated alfuzosin plasma concentrations.
    Escitalopram: (Moderate) Use escitalopram with caution in combination with alfuzosin as concurrent use may increase the risk of QT prolongation. Escitalopram has been associated with a risk of QT prolongation and torsade de pointes (TdP). Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Esmolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Ezogabine: (Moderate) Use caution when administering alfuzosin with ezogabine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Ezogabine has also been associated with QT prolongation.
    Fedratinib: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with fedratinib. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A4 substrate. Fedratinib is a moderate CYP3A4 inhibitor. Coadministration of another moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Felodipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Fingolimod: (Moderate) Use caution when administering alfuzosin with fingolimod due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Additionally, fingolimod initiation results in decreased heart rate and may prolong the QT interval. Fingolimod has not been studied in patients treated with drugs that prolong the QT interval, but drugs that prolong the QT interval have been associated with cases of TdP in patients with bradycardia.
    Flecainide: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with flecainide. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight QT prolonging effect. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Flecainide, a Class IC antiarrhythmic, is also associated with a possible risk for QT prolongation and/or TdP; although, the increase in QT interval is largely due to prolongation of the QRS interval. Causality for TdP has not been established for flecainide.
    Fluconazole: (Contraindicated) Due to the risk of life-threatening arrhythmias such as torsade de pointes (TdP), coadministration of fluconazole with drugs that both prolong the QT interval and are CYP3A4 substrates, such as alfuzosin, is contraindicated. Fluconazole has been associated with QT prolongation and rare cases of TdP. Additonally, fluconazole is an inhibitor of CYP3A4. Coadministration may result in elevated plasma concentrations of alfuzosin, causing an increased risk for adverse events, such as QT prolongation.
    Fluoxetine: (Moderate) Use caution when administering alfuzosin with fluoxetine. Coadministration may increase the risk for QT prolongation and torsade de pointes (TdP). QT prolongation and TdP have been reported in patients treated with fluoxetine. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Fluphenazine: (Minor) Use caution when administering alfuzosin with fluphenazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Fluphenazine is also associated with a possible risk for QT prolongation. Theoretically, fluphenazine may increase the risk of QT prolongation if coadministered with other drugs that have a risk of QT prolongation.
    Fluvoxamine: (Moderate) Use fluvoxamine with caution in combination with alfuzosin as concurrent use may increase the risk of QT prolongation. QT prolongation and torsade de pointes (TdP) has been reported during fluvoxamine postmarketing use. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Food: (Moderate) Alfuzosin extended-release tablets should be taken with food at the same time each day. Alfuzosin absolute bioavailability is 49 percent under fed conditions; under fasting conditions, the extent of absorption is 50 percent lower.
    Fosamprenavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Foscarnet: (Major) When possible, avoid concurrent use of foscarnet with other drugs known to prolong the QT interval, such as alfuzosin. Foscarnet has been associated with postmarketing reports of both QT prolongation and torsade de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. If these drugs are administered together, obtain an electrocardiogram and electrolyte concentrations before and periodically during treatment.
    Fostemsavir: (Moderate) Use caution when administering alfuzosin with fostemsavir due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Supratherapeutic doses of fostemsavir (2,400 mg twice daily, four times the recommended daily dose) have been shown to cause QT prolongation. Fostemsavir causes dose-dependent QT prolongation.
    Gemifloxacin: (Moderate) Use caution when administering alfuzosin with gemifloxacin due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Gemifloxacin may prolong the QT interval in some patients. The maximal change in the QTc interval occurs approximately 5 to 10 hours following oral administration of gemifloxacin. The likelihood of QTc prolongation may increase with increasing dose of the drug; therefore, the recommended dose should not be exceeded especially in patients with renal or hepatic impairment where the Cmax and AUC are slightly higher.
    Gemtuzumab Ozogamicin: (Moderate) Use gemtuzumab ozogamicin and alfuzosin together with caution due to the potential for additive QT interval prolongation and risk of torsade de pointes (TdP). If these agents are used together, obtain an ECG and serum electrolytes prior to the start of gemtuzumab and as needed during treatment. Although QT interval prolongation has not been reported with gemtuzumab, it has been reported with other drugs that contain calicheamicin. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Gilteritinib: (Moderate) Use caution and monitor for evidence of QT prolongation if concurrent use of gilteritinib and alfuzosin is necessary. Gilteritinib has been associated with QT prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Glasdegib: (Major) Avoid coadministration of glasdegib with alfuzosin due to the potential for additive QT prolongation. If coadministration cannot be avoided, monitor patients for increased risk of QT prolongation with increased frequency of ECG monitoring. Glasdegib therapy may result in QT prolongation and ventricular arrhythmias including ventricular fibrillation and ventricular tachycardia. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Goserelin: (Moderate) Consider whether the benefits of androgen deprivation therapy (i.e., goserelin) outweigh the potential risks of QT prolongation in patients receiving alfuzosin. Androgen deprivation therapy may prolong the QT/QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Granisetron: (Moderate) Use granisetron with caution in combination with alfuzosin due to the risk of QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Granisetron has been associated with QT prolongation.
    Grapefruit juice: (Contraindicated) Instruct patients not to consume grapefruit or grapefruit juice while taking alfuzosin. Grapefruit may increase alfuzosin exposure resulting in serious/life-threatening reactions, including hypotension. Alfuzosin is primarily metabolized by CYP3A4; grapefruit is a strong CYP3A4 inhibitor.
    Halofantrine: (Major) Halofantrine is considered to be associated with an increased risk for QT prolongation and torsades de pointes. The need to co-administer halofantrine with drugs known to prolong the QT interval, such as alfuzosin, should be done with a careful assessment of risks versus benefits, and should be avoided when possible.
    Halogenated Anesthetics: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Haloperidol: (Moderate) Caution is advisable when combining haloperidol concurrently with alfuzosin. QT prolongation and torsade de pointes (TdP) have been observed during haloperidol treatment. Excessive doses (particularly in the overdose setting) or IV administration of haloperidol may be associated with a higher risk of QT prolongation. Alfuzosin may also prolong the QT interval in a dose-depndent manner.
    Halothane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Histrelin: (Moderate) Consider whether the benefits of androgen deprivation therapy (i.e., histrelin) outweigh the potential risks of QT prolongation in patients receiving alfuzosin. Androgen deprivation therapy may prolong the QT/QTc interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Hydroxychloroquine: (Major) Avoid coadministration of alfuzosin and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Hydroxyzine: (Moderate) Caution is recommended if hydroxyzine is administered with alfuzosin due to the potential for additive QT prolongation and risk of torsade de pointes (TdP). Postmarketing data indicate that hydroxyzine causes QT prolongation and TdP. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ibutilide: (Major) Ibutilide administration can cause QT prolongation and torsades de pointes (TdP); proarrhythmic events should be anticipated. The potential for proarrhythmic events with ibutilide increases with the coadministration of other drugs that prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Idelalisib: (Contraindicated) Coadministration of alfuzosin and idelalisib is contraindicated due to increased alfuzosin exposure. Idelalisib is a strong CYP3A4 inhibitor. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Iloperidone: (Major) Iloperidone has been associated with QT prolongation; however, torsade de pointes has not been reported. According to the manufacturer, since iloperidone may prolong the QT interval, it should be avoided with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Iloprost: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Imatinib: (Moderate) Alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes; inhibitors of CYP3A4, such as imatinib, are expected to inhibit alfuzosin metabolism and increase systemic exposure to alfuzosin.
    Indapamide: (Moderate) The effects of indapamide may be additive when administered with other antihypertensive agents or diuretics. This may be desirable, but occasionally orthostatic hypotension may occur. Decreased indapamide dosages may be necessary during concomitant use.
    Indinavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Inotuzumab Ozogamicin: (Major) Avoid coadministration of inotuzumab ozogamicin with alfuzosin due to the potential for additive QT interval prolongation and risk of torsade de pointes (TdP). If coadministration is unavoidable, obtain an ECG and serum electrolytes prior to the start of treatment, after treatment initiation, and periodically during treatment. Inotuzumab has been associated with QT interval prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Isavuconazonium: (Moderate) Concomitant use of isavuconazonium with alfuzosin may result in increased serum concentrations of alfuzosin. Alfuzosin is a substrate of the hepatic isoenzyme CYP3A4; isavuconazole, the active moiety of isavuconazonium, is a moderate inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are used together.
    Isoflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Isosorbide Dinitrate, ISDN: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Isosorbide Mononitrate: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Isradipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Itraconazole: (Contraindicated) Alfuzosin is contraindicated for use during itraconazole therapy and is not recommended for 2 weeks after completion of itraconazole therapy. Concurrent use of itraconazole (strong CYP3A4 inhibitor) increases alfuzosin (CYP3A4 substrate) exposure. Both alfuzosin and itraconazole are also associated with QT prolongation; coadministration may increase this risk.
    Ivosidenib: (Major) Avoid coadministration of ivosidenib with alfuzosin due to an increased risk of QT prolongation. If concomitant use is unavoidable, monitor ECGs for QTc prolongation and monitor electrolytes; correct any electrolyte abnormalities as clinically appropriate. An interruption of therapy and dose reduction of ivosidenib may be necessary if QT prolongation occurs. Prolongation of the QTc interval and ventricular arrhythmias have been reported in patients treated with ivosidenib. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ketoconazole: (Contraindicated) Alfuzosin is contraindicated for use with ketoconazole due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ketoconazole is a strong CYP3A4 inhibitor that has been associated with prolongation of the QT interval. Coadministration of ketoconazole increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Labetalol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Lansoprazole; Amoxicillin; Clarithromycin: (Contraindicated) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Lapatinib: (Moderate) Monitor for evidence of QT prolongation if lapatinib is administered with alfuzosin. Both alfuzosin and lapatinib have been associated with concentration-dependent QT prolongation. Ventricular arrhythmias and torsade de pointes (TdP) have been reported in postmarketing experience with lapatinib.
    Lefamulin: (Major) Avoid coadministration of lefamulin with alfuzosin as concurrent use may increase the risk of QT prolongation. If coadministration cannot be avoided, monitor ECG during treatment. Lefamulin has a concentration dependent QTc prolongation effect. The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between lefamulin and other drugs that effect cardiac conduction is unknown. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Lenvatinib: (Major) Avoid coadministration of lenvatinib with alfuzosin due to the risk of QT prolongation. Prolongation of the QT interval has been reported with lenvatinib therapy. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Lesinurad: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of alfuzosin; monitor for potential reduction in efficacy. Alfuzosin is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Lesinurad; Allopurinol: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of alfuzosin; monitor for potential reduction in efficacy. Alfuzosin is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Letermovir: (Moderate) Coadministration of alfuzosin with letermovir may increase alfuzosin exposure and risk for adverse events. Concurrent use is contraindicated if the patient is also receiving cyclosporine because the magnitude of the interaction may be amplified. Alfuzosin is a substrate of CYP3A4. Letermovir is a moderate CYP3A4 inhibitor. The combined effect of letermovir and cyclosporine on CYP3A4 substrates may be similar to a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor with alfuzosin increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Leuprolide: (Moderate) Consider whether the benefits of androgen deprivation therapy (i.e., leuprolide) outweigh the potential risks of QT prolongation in patients receiving alfuzosin. Androgen deprivation therapy may prolong the QT/QTc interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Leuprolide; Norethindrone: (Moderate) Consider whether the benefits of androgen deprivation therapy (i.e., leuprolide) outweigh the potential risks of QT prolongation in patients receiving alfuzosin. Androgen deprivation therapy may prolong the QT/QTc interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Levobetaxolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Levobunolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Levofloxacin: (Moderate) Use caution when administering alfuzosin with levofloxacin due to the potential for QT prolongation and torsade de pointes (TdP). Alfuzosin may prolong the QT interval in a dose-dependent manner. Additionally, levofloxacin has been associated with a risk of QT prolongation and TdP. Although extremely rare, TdP has been reported during postmarketing surveillance of levofloxacin.
    Levoketoconazole: (Contraindicated) Alfuzosin is contraindicated for use with ketoconazole due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ketoconazole is a strong CYP3A4 inhibitor that has been associated with prolongation of the QT interval. Coadministration of ketoconazole increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Levomethadyl: (Contraindicated) Levomethadyl is associated with an established risk of QT prolongation and/or torsades de pointes and is contraindicated in combination with other agents that may prolong the QT interval, such as alfuzosin.
    Lithium: (Moderate) Lithium should be used cautiously and with close monitoring with alfuzosin as concurrent use may increase the risk of QT prolongation. Lithium has been associated with QT prolongation. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Lofexidine: (Major) Monitor ECG if lofexidine is coadministered with alfuzosin due to the potential for additive QT prolongation. Lofexidine prolongs the QT interval. In addition, there are postmarketing reports of torsade de pointes. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Alfuzosin is an alpha-blocker that does not commonly result in a drop in blood pressure, however, additive effects on blood pressure may also occur.
    Lonafarnib: (Contraindicated) Coadministration of alfuzosin and lonafarnib is contraindicated due to increased alfuzosin exposure. Alfuzosin is a CYP3A4 substrate and lonafarnib is a strong CYP3A4 inhibitor. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Loperamide: (Moderate) Use caution when administering alfuzosin with loperamide due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. At high doses, loperamide has been associated with serious cardiac toxicities, including syncope, ventricular tachycardia, QT prolongation, torsade de pointes (TdP), and cardiac arrest.
    Loperamide; Simethicone: (Moderate) Use caution when administering alfuzosin with loperamide due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. At high doses, loperamide has been associated with serious cardiac toxicities, including syncope, ventricular tachycardia, QT prolongation, torsade de pointes (TdP), and cardiac arrest.
    Lopinavir; Ritonavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Lumacaftor; Ivacaftor: (Minor) Lumacaftor; ivacaftor may reduce the efficacy of alfuzosin by decreasing its systemic exposure. If used together, monitor the patient for appropriate clinical effects. Alfuzosin is a CYP3A4 substrate. Lumacaftor is a strong CYP3A inducer.
    Macimorelin: (Major) Avoid concurrent administration of macimorelin with drugs that prolong the QT interval, such as alfuzosin. Use of these drugs together may increase the risk of developing torsade de pointes-type ventricular tachycardia. Sufficient washout time of drugs that are known to prolong the QT interval prior to administration of macimorelin is recommended. Treatment with macimorelin has been associated with an increase in the corrected QT (QTc) interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Maprotiline: (Moderate) Use caution when administering alfuzosin with maprotiline due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Maprotiline has been reported to prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Cases of long QT syndrome and torsade de pointes (TdP) tachycardia have been described with maprotiline use, but rarely occur when the drug is used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of maprotiline in combination with other QT-prolonging drugs.
    Mefloquine: (Moderate) Mefloquine should be used with caution in patients receiving alfuzosin as concurrent use may increase the risk of QT prolongation. There is evidence that the use of halofantrine after mefloquine causes a significant lengthening of the QTc interval. Mefloquine alone has not been reported to cause QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Meperidine; Promethazine: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Mesoridazine: (Contraindicated) Alfuzosin has a slight effect to prolong the QT interval and should be used cautiously in combination with other drugs that may also prolong the QT interval including mesoridazine.
    Methadone: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and methadone should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Methadone is considered to be associated with an increased risk for QT prolongation and torsades de pointes (TdP), especially at higher doses (> 200 mg/day but averaging approximately 400 mg/day in adult patients). Laboratory studies, both in vivo and in vitro, have demonstrated that methadone inhibits cardiac potassium channels and prolongs the QT interval. Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction.
    Metoprolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Metronidazole: (Moderate) Concomitant use of metronidazole and alfuzosin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
    Midostaurin: (Major) The concomitant use of midostaurin and alfuzosin may lead to additive QT interval prolongation. If these drugs are used together, consider obtaining electrocardiograms to monitor the QT interval. In clinical trials, QT prolongation was reported in patients who received midostaurin as single-agent therapy or in combination with cytarabine and daunorubicin. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Mifepristone: (Contraindicated) Alfuzosin is contraindicated for use with mifepristone due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; mifepristone is a strong CYP3A4 inhibitor that has also been associated with dose-dependent prolongation of the QT interval. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Mirtazapine: (Moderate) Use caution when using mirtazapine in combination with alfuzosin. Both alfuzosin and mirtazapine have been associated with dose-dependent prolongation of the QT interval. Torsade de pointes (TdP) has been reported postmarketing in treatment with mirtazapine, primarily in overdose or in patients with other risk factors for QT prolongation.
    Mitotane: (Moderate) Use caution if mitotane and alfuzosin are used concomitantly, and monitor for decreased efficacy of alfuzosin and a possible change in dosage requirements. Mitotane is a strong CYP3A4 inducer and alfuzosin is a CYP3A4 substrate; coadministration may result in decreased plasma concentrations of alfuzosin.
    Mobocertinib: (Major) Concomitant use of mobocertinib and alfuzosin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
    Moxifloxacin: (Major) Concurrent use of alfuzosin and moxifloxacin should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Moxifloxacin has been associated with prolongation of the QT interval. Additionally, post-marketing surveillance has identified very rare cases of ventricular arrhythmias including TdP, usually in patients with severe underlying proarrhythmic conditions. The likelihood of QT prolongation may increase with increasing concentrations of moxifloxacin, therefore the recommended dose or infusion rate should not be exceeded. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Nadolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Nebivolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Nebivolol; Valsartan: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Nefazodone: (Contraindicated) Alfuzosin is contraindicated for use with nefazodone due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; nefazodone is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Nelfinavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Nicardipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nifedipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nilotinib: (Major) Avoid the concomitant use of nilotinib with other agents that prolong the QT interval, such as alfuzosin. Additionally, nilotinib is a moderate inhibitor of CYP3A4 and alfuzosin is a substrate of CYP3A4; administering these drugs together may result in increased alfuzosin levels. If the use of alfuzosin is necessary, hold nilotinib therapy. If these drugs are used together, consider an alfuzosin dose reduction and monitor patients for toxicity (e.g., QT interval prolongation).
    Nirmatrelvir; Ritonavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors. (Contraindicated) Concomitant use of ritonavir-boosted nirmatrelvir and alfuzosin is contraindicated; consider an alternative COVID-19 therapy. Coadministration may increase alfuzosin exposure resulting in increased toxicity. Alfuzosin is a CYP3A substrate and nirmatrelvir is a CYP3A inhibitor.
    Nisoldipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nitrates: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Nitroglycerin: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Octreotide: (Moderate) Use octreotide with caution in combination with alfuzosin as concurrent use may increase the risk of QT prolongation. Arrhythmias, sinus bradycardia, and conduction disturbances have occurred during octreotide therapy. Since bradycardia is a risk factor for development of torsade de pointes (TdP), the potential occurrence of bradycardia during octreotide administration could theoretically increase the risk of TdP in patients receiving drugs that prolong the QT interval. Additionally, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ofloxacin: (Moderate) Use caution when administering alfuzosin with ofloxacin due to the potential for QT prolongation. Quinolones have been associated with a risk of QT prolongation and torsade de pointes (TdP). Although extremely rare, TdP has been reported during postmarketing surveillance of ofloxacin. These reports generally involved patients with concurrent medical conditions or concomitant medications that may have been contributory. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Olanzapine: (Moderate) Caution is advised when administering olanzapine with alfuzosin as concurrent use may increase the risk of QT prolongation. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Olanzapine; Fluoxetine: (Moderate) Caution is advised when administering olanzapine with alfuzosin as concurrent use may increase the risk of QT prolongation. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner. (Moderate) Use caution when administering alfuzosin with fluoxetine. Coadministration may increase the risk for QT prolongation and torsade de pointes (TdP). QT prolongation and TdP have been reported in patients treated with fluoxetine. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Olanzapine; Samidorphan: (Moderate) Caution is advised when administering olanzapine with alfuzosin as concurrent use may increase the risk of QT prolongation. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Ombitasvir; Paritaprevir; Ritonavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Ondansetron: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), ondansetron and alfuzosin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Ondansetron has been associated with a dose-related increase in the QT interval and postmarketing reports of torsade de pointes (TdP). If ondansetron and alfuzosin must be coadministered, ECG monitoring is recommended.
    Oritavancin: (Moderate) Alfuzosin is metabolized by CYP3A4; oritavancin is a weak CYP3A4 inducer. Plasma concentrations and efficacy of alfuzosin may be reduced if these drugs are administered concurrently.
    Osilodrostat: (Moderate) Monitor ECGs in patients receiving osilodrostat with alfuzosin. Osilodrostat is associated with dose-dependent QT prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Osimertinib: (Major) Avoid coadministration of alfuzosin with osimertinib if possible due to the risk of QT prolongation and torsade de pointes (TdP). If concomitant use is unavoidable, periodically monitor ECGs for QT prolongation and monitor electrolytes; an interruption of osimertinib therapy with dose reduction or discontinuation of therapy may be necessary if QT prolongation occurs. Concentration-dependent QTc prolongation occurred during clinical trials of osimertinib. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Oxaliplatin: (Major) Monitor ECGs and electrolytes in patients receiving oxaliplatin and alfuzosin concomitantly; correct electrolyte abnormalities prior to administration of oxaliplatin. QT prolongation and ventricular arrhythmias including fatal torsade de pointes have been reported with oxaliplatin use in postmarketing experience. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Oxymetazoline: (Major) Caution is advised when administering alfuzosin with oxymetazoline. Alfuzosin, an alpha adrenergic blocker, would likely antagonize the sympathomimetic effects of oxymetazoline, alpha adrenergic agonists; thereby reducing the effectiveness of oxymetazoline.
    Ozanimod: (Major) In general, do not initiate ozanimod in patients taking alfuzosin due to the risk of additive bradycardia, QT prolongation, and torsade de pointes (TdP). If treatment initiation is considered, seek advice from a cardiologist. Ozanimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ozanimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with TdP in patients with bradycardia. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Pacritinib: (Major) Concomitant use of pacritinib and alfuzosin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
    Paliperidone: (Major) Paliperidone has been associated with QT prolongation; torsade de pointes (TdP) and ventricular fibrillation have been reported in the setting of overdose. According to the manufacturer, since paliperidone may prolong the QT interval, it should be avoided in combination with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. If coadministration is considered necessary by the practitioner, and the patient has known risk factors for cardiac disease or arrhythmia, close monitoring is essential.
    Panobinostat: (Major) QT prolongation has been reported with panobinostat therapy in patients with multiple myeloma in a clinical trial; use of panobinostat with other agents that prolong the QT interval is not recommended. Obtain an electrocardiogram at baseline and periodically during treatment. Hold panobinostat if the QTcF increases to >= 480 milliseconds during therapy; permanently discontinue if QT prolongation does not resolve. Drugs with a possible risk for QT prolongation and torsade de pointes that should be used cautiously and with close monitoring with panobinostat include alfuzosin.
    Pasireotide: (Moderate) Use caution when administering alfuzosin with pasireotide due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. QT prolongation has occurred with pasireotide at therapeutic and supra-therapeutic doses.
    Pazopanib: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and pazopanib should be avoided. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Coadministration of pazopanib and other drugs that prolong the QT interval is not advised; pazopanib has been reported to prolong the QT interval. If pazopanib and the other drug must be continued, closely monitor the patient for QT interval prolongation.
    Penbutolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Pentamidine: (Major) Pentamidine has been associated with QT prolongation and torsade de pointes. Drugs with a possible risk for QT prolongation include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use caution in co-administration.
    Perphenazine: (Minor) Use caution when administering alfuzosin with perphenazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Perphenazine is also associated with a possible risk for QT prolongation.
    Perphenazine; Amitriptyline: (Minor) Use caution when administering alfuzosin with perphenazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Perphenazine is also associated with a possible risk for QT prolongation.
    Phenoxybenzamine: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Phentolamine: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Pimavanserin: (Major) Pimavanserin may cause QT prolongation and should generally be avoided in patients receiving other medications known to prolong the QT interval, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Coadministration may increase the risk for QT prolongation.
    Pimozide: (Contraindicated) Because of the potential for QT prolongation and torsade de pointes (TdP), use of alfuzosin with pimozide is contraindicated. Pimozide is associated with a well-established risk of QT prolongation and TdP. Based on electrophysiology studies, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Pindolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Pitolisant: (Major) Avoid coadministration of pitolisant with alfuzosin as concurrent use may increase the risk of QT prolongation. Pitolisant prolongs the QT interval. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ponesimod: (Major) In general, do not initiate ponesimod in patients taking alfuzosin due to the risk of additive bradycardia, QT prolongation, and torsade de pointes (TdP). If treatment initiation is considered, seek advice from a cardiologist. Ponesimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ponesimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with TdP in patients with bradycardia. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Posaconazole: (Contraindicated) Alfuzosin is contraindicated for use with posaconazole due to the potential for serious/life-threatening reactions, including hypotension and QT prolongation. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; posaconazole is a strong CYP3A4 inhibitor that has been associated with prolongation of the QT interval as well as rare cases of torsade de pointes. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Prazosin: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Primaquine: (Moderate) Use caution when administering alfuzosin with primaquine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Primaquine also has the potential to prolong the QT interval.
    Procainamide: (Major) Alfuzosin should be used cautiously with procainamide. Procainamide is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Prochlorperazine: (Minor) Use caution when administering alfuzosin with prochlorperazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Prochlorperazine is also associated with a possible risk for QT prolongation.
    Promethazine: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Promethazine; Dextromethorphan: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Promethazine; Phenylephrine: (Moderate) Use caution when administering alfuzosin with promethazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Promethazine, a phenothiazine, is also associated with a possible risk for QT prolongation.
    Propafenone: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering propafenone with alfuzosin. Propafenone is a Class IC antiarrhythmic which increases the QT interval, but largely due to prolongation of the QRS interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin also has a slight QT prolonging effect. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Propranolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Protease inhibitors: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Quetiapine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), coadministration of alfuzosin and quetiapine should be avoided. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Limited data, including some case reports, suggest that quetiapine may also be associated with a significant prolongation of the QTc interval in rare instances. Concurrent use may result in additive effects on the QT interval.
    Quinidine: (Major) Alfuzosin should be used cautiously with quinidine. Quinidine administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Quinine: (Major) Concurrent use of quinine and alfuzosin should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Quinine has been associated with prolongation of the QT interval and rare cases of TdP. Based on electrophysiology studies performed by the manufacturer, alfuzosin also has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. In addition, concentrations of alfuzosin may be increased with concomitant use of quinine. Alfuzosin is a CYP3A4 substrate and quinine is a CYP3A4 inhibitor.
    Ranolazine: (Moderate) Use caution when administering alfuzosin with ranolazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Ranolazine is associated with dose- and plasma concentration-related increases in the QTc interval. Although there are no studies examining the effects of ranolazine in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation.
    Relugolix: (Moderate) Consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients receiving other QT prolonging agents such as alfuzosin. Androgen deprivation therapy (i.e., relugolix) may prolong the QT/QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Relugolix; Estradiol; Norethindrone acetate: (Moderate) Consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients receiving other QT prolonging agents such as alfuzosin. Androgen deprivation therapy (i.e., relugolix) may prolong the QT/QTc interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Ribociclib: (Contraindicated) Alfuzosin is contraindicated for use with ribociclib due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ribociclib is a strong CYP3A4 inhibitor that has also been shown to prolong the QT interval in a concentration-dependent manner. Concomitant use may increase the risk for QT prolongation.
    Ribociclib; Letrozole: (Contraindicated) Alfuzosin is contraindicated for use with ribociclib due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ribociclib is a strong CYP3A4 inhibitor that has also been shown to prolong the QT interval in a concentration-dependent manner. Concomitant use may increase the risk for QT prolongation.
    Rilpivirine: (Moderate) Caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Risperidone: (Moderate) Use risperidone and alfuzosin together with caution due to the potential for additive QT prolongation and risk of torsade de pointes (TdP). Risperidone has been associated with a possible risk for QT prolongation and/or TdP, primarily in the overdose setting. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ritonavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Romidepsin: (Moderate) Consider monitoring electrolytes and ECGs at baseline and periodically during treatment if romidepsin is administered with alfuzosin. Romidepsin has been reported to prolong the QT interval and alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Saquinavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Selpercatinib: (Major) Monitor ECGs more frequently for QT prolongation if coadministration of selpercatinib with alfuzosin is necessary due to the risk of additive QT prolongation. Concentration-dependent QT prolongation has been observed with selpercatinib therapy. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Sertraline: (Moderate) Use caution and monitor patients for QT prolongation when administering alfuzosin with sertraline. Alfuzosin may prolong the QT interval in a dose-dependent manner. Sertraline's FDA-approved labeling recommends avoiding concomitant use with drugs known to prolong the QTc interval; however, the risk of sertraline-induced QT prolongation is generally considered to be low in clinical practice. Its effect on QTc interval is minimal (typically less than 5 msec), and the drug has been used safely in patients with cardiac disease (e.g., recent myocardial infarction, unstable angina, chronic heart failure).
    Sevoflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Sildenafil: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on alfuzosin therapy before initiating therapy with the lowest dose of sildenafil. Conversely, patients already receiving an optimized dose of sildenafil should be started on the lowest dose of alfuzosin; increases in the alpha-blocker dose should be done in a stepwise fashion. Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of sildenafil and alfuzosin.
    Silodosin: (Contraindicated) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Simeprevir: (Moderate) Simeprevir, a mild intestinal CYP3A4 inhibitor, may increase the side effects of alfuzosin, which is a CYP3A4 substrate. Monitor patients for adverse effects of alfuzosin, such as dizziness, hypotension, and syncope.
    Siponimod: (Major) In general, do not initiate treatment with siponimod in patients receiving alfuzosin due to the potential for QT prolongation. Consult a cardiologist regarding appropriate monitoring if siponimod use is required. Siponimod therapy prolonged the QT interval at recommended doses in a clinical study. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Solifenacin: (Moderate) Use caution when administering alfuzosin with solifenacin due to the potential for QT prolongation. Both alfuzosin and solifenacin may prolong the QT interval in a dose-dependent manner. Additionally, torsade de pointes (TdP) has been reported with postmarketing use of solifenacin, although causality was not determined.
    Sorafenib: (Major) Avoid coadministration of sorafenib with alfuzosin due to the risk of additive QT prolongation. If concomitant use is unavoidable, monitor electrocardiograms and correct electrolyte abnormalities. An interruption or discontinuation of sorafenib therapy may be necessary if QT prolongation occurs. Sorafenib is associated with QTc prolongation. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Sotalol: (Major) Use caution during concurrent administration. Sotalol administration is associated with QT prolongation and torsades de pointes (TdP). Proarrhythmic events should be anticipated after initiation of therapy and after each upward dosage adjustment. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Sunitinib: (Moderate) Use caution and monitor for evidence of QT prolongation if sunitinib is administered with alfuzosin. Sunitinib can prolong the QT interval. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Tacrolimus: (Moderate) Consider ECG and electrolyte monitoring periodically during treatment if tacrolimus is administered with alfuzosin as concurrent use may increase the risk of QT prolongation. Tacrolimus may prolong the QT interval and cause torsade de pointes (TdP). Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Tadalafil: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on alfuzosin therapy before initiating therapy with the lowest recommended dose of tadalafil. Conversely, patients already receiving an optimized dose of tadalafil should be started on the lowest dose of alfuzosin; increases in the alpha-blocker dose should be done in a stepwise fashion. When tadalafil is used for benign prostatic hypertrophy (BPH), discontinue alfuzosin therapy at least 1 day prior to initiating tadalafil therapy. Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of tadalafil and alfuzosin.
    Tamoxifen: (Moderate) Caution is advised with the concomitant use of tamoxifen with alfuzosin due to an increased risk of QT prolongation. Tamoxifen has been reported to prolong the QT interval, usually in overdose or when used in high doses. Rare case reports of QT prolongation have also been described when tamoxifen is used at lower doses. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Telaprevir: (Contraindicated) The concurrent use of alfuzosin and telaprevir is contraindicated due to the potential for serious/life-threatening reactions. Telaprevir is an inhibitor of CYP3A4, which is responsible for alfuzosin metabolism. Coadministration may result in large increases in alfuzosin serum concentrations, which could cause adverse events such as hypotension and cardiac arrhythmias.
    Telavancin: (Moderate) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering telavancin with alfuzosin. Telavancin has been associated with QT prolongation. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Telithromycin: (Contraindicated) Alfuzosin is contraindicated for use with telithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; telithromycin is a strong CYP3A4 inhibitor that is associated with QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Terazosin: (Major) Alfuzosin should not be administered in combination with other alpha-blockers. The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects.
    Tetrabenazine: (Major) Tetrabenazine causes a small increase in the corrected QT interval (QTc). The manufacturer recommends avoiding concurrent use of tetrabenazine with other drugs known to prolong QTc, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Thioridazine: (Contraindicated) Thioridazine is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Thioridazine is considered contraindicated for use along with agents that, when combined with a phenothiazine, may prolong the QT interval and increase the risk of TdP, and/or cause orthostatic hypotension. Because of the potential for TdP, use of alfuzosin with thioridazine is contraindicated.
    Timolol: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Tipranavir: (Contraindicated) Coadministration of alfuzosin with protease inhibitors is contraindicated due to potential hypotension. Alfuzosin is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors.
    Tolterodine: (Moderate) Use caution when administering alfuzosin with tolterodine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Tolterodine has also been associated with dose-dependent prolongation of the QT interval, especially in poor CYP2D6 metabolizers.
    Toremifene: (Major) Avoid coadministration of alfuzosin with toremifene if possible due to the risk of additive QT prolongation. If concomitant use is unavoidable, closely monitor ECGs for QT prolongation and monitor electrolytes; correct hypokalemia or hypomagnesemia prior to administration of toremifene. Toremifene has been shown to prolong the QTc interval in a dose- and concentration-related manner. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Trandolapril; Verapamil: (Moderate) Monitor blood pressure if coadministration of alfuzosin and verapamil is necessary. This combination has the potential to cause hypotension in some patients. Coadministration may also result in increased alfuzosin serum concentrations. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. In addition to potential for additive hypotension with alfuzosin, verapamil may also inhibit the metabolism of alfuzosin.
    Trazodone: (Major) Trazodone should be avoided in combination with alfuzosin. Trazodone can prolong the QT/QTc interval at therapeutic doses. In addition, there are post-marketing reports of torsade de pointes (TdP). Therefore, the manufacturer recommends avoiding trazodone in patients receiving other drugs that increase the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Triclabendazole: (Moderate) Monitor ECGs in patients receiving triclabendazole with alfuzosin. Transient prolongation of the mean QTc interval was noted on the ECG recordings in dogs administered triclabendazole. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Trifluoperazine: (Minor) Use caution when administering alfuzosin with trifluoperazine due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Trifluoperazine is also associated with a possible risk for QT prolongation.
    Triptorelin: (Moderate) Consider whether the benefits of androgen deprivation therapy (i.e., triptorelin) outweigh the potential risks of QT prolongation in patients receiving alfuzosin. Androgen deprivation therapy may prolong the QT/QTc interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Tucatinib: (Contraindicated) Coadministration of alfuzosin and tucatinib is contraindicated due to increased alfuzosin exposure. Alfuzosin is a CYP3A4 substrate; tucatinib is a strong CYP3A4 inhibitor. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Vandetanib: (Major) Avoid coadministration of vandetanib with alfuzosin due to an increased risk of QT prolongation and torsade de pointes (TdP). If concomitant use is unavoidable, monitor ECGs for QT prolongation and monitor electrolytes; correct hypocalcemia, hypomagnesemia, and/or hypomagnesemia prior to vandetanib administration. An interruption of vandetanib therapy or dose reduction may be necessary for QT prolongation. Vandetanib can prolong the QT interval in a concentration-dependent manner; TdP and sudden death have been reported in patients receiving vandetanib. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Vardenafil: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on alfuzosin therapy before initiating therapy with the lowest starting dose of vardenafil. Conversely, patients already receiving an optimized dose of vardenafil should be started on the lowest dose of alfuzosin; increases in the alpha-blocker dose should be done in a stepwise fashion. Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of vardenafil and alfuzosin. Concurrent use of these medications may also increase the risk for QT prolongation. Vardenafil is associated with QT prolongation. Both therapeutic and supratherapeutic doses of vardenafil produce an increase in QTc interval. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Vemurafenib: (Major) Vemurafenib has been associated with QT prolongation. If vemurafenib and another drug, such as alfuzosin, that is associated with a possible risk for QT prolongation and torsade de pointes (TdP) must be coadministered, ECG monitoring is recommended; closely monitor the patient for QT interval prolongation. In addition to avoiding concurrent drug interactions, the potential for TdP can be reduced by avoiding the use of QT prolonging drugs in patients at substantial risk for TdP. Examples of general risk factors for TdP include congenital long QT syndrome, female sex, elderly patients, significant bradycardia, hypokalemia, hypomagnesemia, and underlying cardiac disease (e.g., arrhythmias, cardiomyopathy, acute myocardial ischemia). Also, alfuzosin is a CYP3A4 substrate, while vemurafenib is a CYP3A4 substrate and inducer; therefore, concentrations of alfuzosin may be decreased.
    Venlafaxine: (Moderate) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and venlafaxine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Venlafaxine administration is associated with a possible risk of QT prolongation; TdP has reported with postmarketing use.
    Verapamil: (Moderate) Monitor blood pressure if coadministration of alfuzosin and verapamil is necessary. This combination has the potential to cause hypotension in some patients. Coadministration may also result in increased alfuzosin serum concentrations. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. In addition to potential for additive hypotension with alfuzosin, verapamil may also inhibit the metabolism of alfuzosin.
    Voclosporin: (Moderate) Concomitant use of voclosporin and alfuzosin may increase the risk of QT prolongation. Consider interventions to minimize the risk of progression to torsades de pointes (TdP), such as ECG monitoring and correcting electrolyte abnormalities, particularly in patients with additional risk factors for TdP. Voclosporin has been associated with QT prolongation at supratherapeutic doses. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Voriconazole: (Contraindicated) Alfuzosin is contraindicated for use with voriconazole due to the potential for serious/life-threatening reactions, including hypotension and QT prolongation. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; voriconazole is a strong CYP3A4 inhibitor that has been associated with QT prolongation and rare cases of torsade de pointes. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Vorinostat: (Moderate) Use caution when administering alfuzosin with vorinostat due to the potential for QT prolongation. Alfuzosin may prolong the QT interval in a dose-dependent manner. Vorinostat therapy is also associated with a risk of QT prolongation.
    Voxelotor: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with voxelotor. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A substrate; voxelotor is a moderate CYP3A inhibitor. Coadministration of another moderate CYP3A inhibitor increased the alfuzosin AUC by 1.3-fold.
    Ziprasidone: (Major) Concomitant use of ziprasidone and alfuzosin should be avoided due to the potential for additive QT prolongation. Clinical trial data indicate that ziprasidone causes QT prolongation; there are postmarketing reports of torsade de pointes (TdP) in patients with multiple confounding factors. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.

    PREGNANCY AND LACTATION

    Pregnancy

    Alfuzosin is not indicated for use in females; therefore, no adequate well-controlled studies in pregnant women have been done to assess the safety of alfuzosin use during pregnancy. Alfuzosin was not teratogenic, embryotoxic or fetotoxic in rats at plasma exposure levels (based on AUC of unbound drug) up to 1,200-times the maximum recommended human dose (MRHD) of 10 mg/day. In rabbits administered up to 3-times the MRHD (based on body surface area) no embryofetal toxicity or teratogenicity was observed. Gestation was slightly prolonged in rats at exposure levels approximately 12-times the MRHD, but difficulties with parturition were not observed.

    There is no known use of alfuzosin in breast-feeding mothers; it is not known whether alfuzosin distributes into breast milk.

    MECHANISM OF ACTION

    Alfuzosin is a selective antagonist at alpha-1 receptors. Blockade of these receptors by alfuzosin can cause smooth muscles in the bladder neck and prostate to relax, thereby reducing pressure on the urethra and improving urine flow rate. This results in a reduction in the symptoms of benign prostatic hypertrophy (BPH) and improves urinary flow. Alpha-1 receptors are involved in contraction of smooth muscle and are abundant in the prostate, prostatic capsule, prostatic urethra, bladder base, and bladder neck. Three subtypes of alpha-1 receptors have been identified: Alpha-1a, alpha-1b, and alpha-1d. Alpha-1a receptors mediate human prostatic smooth muscle contraction whereas alpha-1b and alpha-1d receptors are involved in vascular smooth muscle contraction. Both alpha-1a and alpha-1b receptors exist in the prostate, however, approximately 70% of the alpha receptors in the human prostate are of the alpha-1a subtype. Similar to tamsulosin, alfuzosin appears to be more specific for alpha-1a receptors than other alpha-1 blockers.

    PHARMACOKINETICS

    Alfuzosin is administered orally as a sustained-release dosage form. Steady-state plasma concentrations are attained after a second dose and are 1.2- to 1.6-fold higher than those following single doses. In the systemic circulation, it is approximately 82% to 90% protein bound. Penetration into the CNS is low. Alfuzosin is extensively metabolized by the liver to inactive metabolites; the metabolic pathways involved are oxidation, O-demethylation, and N-dealkylation. CYP3A4 is the principal hepatic enzyme involved in metabolism. About 11% of the parent compound is excreted unchanged in the urine. The metabolites are primarily excreted in the feces. Radiolabeled studies show 69% of an administered dose is excreted in the feces and 24% in the urine. The terminal elimination half-life is about 10 hours. Multiple dosing does not affect the elimination half-life.
     
    Affected cytochrome P450 (CYP450) isoenzymes and drug transporters: CYP3A4
    CYP3A4 is the principal enzyme involved in alfuzosin metabolism. Potent inhibitors of CYP3A4 are contraindicated for use with alfuzosin, as alfuzosin blood concentrations are greatly increased (approximately 2 to 3-fold) in the presence of such inhibitors. Alfuzosin does not inhibit CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6 or CYP3A4; it does not induce CYP1A, CYP2A6, or CYP3A4.

    Oral Route

    Alfuzosin extended-release tablets are absorbed rapidly with an absolute bioavailability of 49% under fed conditions once released. Under fasting conditions, the extent of absorption is 50% lower. The extended-release tablets must be taken with food and not on an empty stomach. The time to peak concentration (Tmax) is 8 hours.