CONTRAINDICATIONS / PRECAUTIONS
Cardiac arrhythmias, hypercalcemia, hypercalciuria, hyperphosphatemia, hypervitaminosis D, seizures
Hypercalcemia may occur with calcifediol treatment. Acute hypercalcemia may increase the risk of cardiac arrhythmias and seizures and may potentiate the effect of digitalis on the heart. Chronic hypercalcemia may lead to generalized vascular calcification and other soft-tissue calcifications. Severe hypercalcemia due to substantial overdosage of vitamin D (hypervitaminosis D) and its metabolites may require emergency treatment. Hypercalcemia may be worsened by concomitant administration of high doses of calcium containing preparations, thiazide diuretics, or other vitamin D compounds. Additionally, high intake of calcium and phosphate concomitantly with vitamin D compounds may lead to hypercalciuria and hyperphosphatemia. Monitor serum calcium frequently in these situations; dose adjustments of calcifediol may be necessary. Monitor patients with a history of hypercalcemia prior to starting treatment more frequently during therapy. Instruct patients to be aware of the symptoms of elevated calcium, such as feeling tired, difficulty thinking clearly, loss of appetite, nausea, vomiting, constipation, increased thirst and urination, and weight loss.
Bone fractures
Adynamic bone disease with subsequent increased risk of bone fractures may develop if intact parathyroid hormone (iPTH) is suppressed to abnormally low concentrations. Monitor iPTH concentrations during therapy and adjust calcifediol dose if needed.
Dialysis, renal disease
The safety and efficacy of calcifediol in patients with Stage 2 or Stage 5 chronic kidney disease and patients with end-stage renal disease on dialysis have not been established.
Pregnancy
There are no adequate and well-controlled studies of calcifediol use in human pregnancy. In animal reproduction studies in rabbits, calcifediol increased skeletal and soft tissue malformation when given in doses of 6 to 13 times the human dose of 60 mcg/day, based on body surface area, during organogenesis. No adverse developmental outcomes were noted in rats given up to 15 times the human dose, based on body surface area, during organogenesis.
Breast-feeding
There are no data available on the presence of calcifediol in human milk, the effect on the breastfed infant or the effect on milk production. Monitor infants exposed to calcifediol through breast milk for signs and symptoms of hypercalcemia, including seizures, vomiting, constipation, and weight loss. Consider monitoring of serum calcium in the infant. Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for calcifediol and any potential adverse effects on the breast-fed infant from calcifediol or the underlying maternal condition.
DRUG INTERACTIONS
Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Aluminum Hydroxide: (Moderate) The chronic use of aluminum-containing antacids for hyperphosphatemia in conjunction with vitamin D analogs can lead to increased aluminum concentrations and toxicity. This is of primary significance in patients with chronic renal failure. Aluminum hydroxide may be used as a phosphate binder in patients receiving vitamin D analogs. The serum phosphate, calcium and calculated calcium-phosphate product (serum Ca x PO4) should be monitored closely. After initiating vitamin D analog therapy, the dose of phosphate binders should be decreased to correct persistent mild hypercalcemia or increased to correct persistent mild hyperphosphatemia.
Aluminum Hydroxide; Magnesium Carbonate: (Moderate) The chronic use of aluminum-containing antacids for hyperphosphatemia in conjunction with vitamin D analogs can lead to increased aluminum concentrations and toxicity. This is of primary significance in patients with chronic renal failure. Aluminum hydroxide may be used as a phosphate binder in patients receiving vitamin D analogs. The serum phosphate, calcium and calculated calcium-phosphate product (serum Ca x PO4) should be monitored closely. After initiating vitamin D analog therapy, the dose of phosphate binders should be decreased to correct persistent mild hypercalcemia or increased to correct persistent mild hyperphosphatemia.
Aluminum Hydroxide; Magnesium Hydroxide: (Moderate) Magnesium-containing antacids, such as magnesium hydroxide, should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, concomitant use should be avoided, if possible, in patients with chronic renal failure. (Moderate) The chronic use of aluminum-containing antacids for hyperphosphatemia in conjunction with vitamin D analogs can lead to increased aluminum concentrations and toxicity. This is of primary significance in patients with chronic renal failure. Aluminum hydroxide may be used as a phosphate binder in patients receiving vitamin D analogs. The serum phosphate, calcium and calculated calcium-phosphate product (serum Ca x PO4) should be monitored closely. After initiating vitamin D analog therapy, the dose of phosphate binders should be decreased to correct persistent mild hypercalcemia or increased to correct persistent mild hyperphosphatemia.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Magnesium-containing antacids, such as magnesium hydroxide, should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, concomitant use should be avoided, if possible, in patients with chronic renal failure. (Moderate) The chronic use of aluminum-containing antacids for hyperphosphatemia in conjunction with vitamin D analogs can lead to increased aluminum concentrations and toxicity. This is of primary significance in patients with chronic renal failure. Aluminum hydroxide may be used as a phosphate binder in patients receiving vitamin D analogs. The serum phosphate, calcium and calculated calcium-phosphate product (serum Ca x PO4) should be monitored closely. After initiating vitamin D analog therapy, the dose of phosphate binders should be decreased to correct persistent mild hypercalcemia or increased to correct persistent mild hyperphosphatemia.
Aluminum Hydroxide; Magnesium Trisilicate: (Moderate) The chronic use of aluminum-containing antacids for hyperphosphatemia in conjunction with vitamin D analogs can lead to increased aluminum concentrations and toxicity. This is of primary significance in patients with chronic renal failure. Aluminum hydroxide may be used as a phosphate binder in patients receiving vitamin D analogs. The serum phosphate, calcium and calculated calcium-phosphate product (serum Ca x PO4) should be monitored closely. After initiating vitamin D analog therapy, the dose of phosphate binders should be decreased to correct persistent mild hypercalcemia or increased to correct persistent mild hyperphosphatemia.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with clarithromycin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with clarithromycin. Clarithromycin, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Atazanavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with atazanavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with atazanavir. Atazanavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Atazanavir; Cobicistat: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with atazanavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with atazanavir. Atazanavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Atenolol; Chlorthalidone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Azilsartan; Chlorthalidone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Barbiturates: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with barbiturates. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with barbiturates. Barbiturates stimulate microsomal hydroxylation and reduce the half-life of calcifediol. In rare cases, this has caused anticonvulsant-induced rickets and osteomalacia.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Bendroflumethiazide; Nadolol: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Burosumab: (Contraindicated) Vitamin D analogs are contraindicated in patients receiving burosumab; discontinue vitamin D analogs 1 week prior to initiation of burosumab.
Calcitonin: (Moderate) Calcitonin is given to hypercalcemic patients to reduce serum calcium concentrations. For the treatment of hypercalcemia, vitamin D preparations should be avoided. Vitamin D analogs can elevate serum calcium concentrations and antagonize the effects of the calcitonin for this condition. For the treatment of osteoporosis adequate intake of vitamin D is necessary in conjunction with calcitonin. An increase in serum calcium concentrations helps to reduce bone resorption and loss of bone mass, and offsets the effect of calcitonin in lowering serum calcium levels.
Calcitriol: (Major) Withhold calcifediol treatment when using other vitamin D analogs, like calcitrol, due to the risk of additive toxicity including hypercalcemia, hypercalciuria, and hyperphosphatemia.
Calcium Acetate: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate; Magnesium Hydroxide: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate; Risedronate: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Carbonate; Simethicone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Chloride: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium Gluconate: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Calcium; Vitamin D: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Chlorothiazide: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Chlorthalidone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Chlorthalidone; Clonidine: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Cholestyramine: (Moderate) Separate administration of calcifediol by 1 hour before or 4 hours after a cholestyramine dose to limit effects on oral absorption. Dose adjustment of calcifediol may be necessary during coadministration with cholestyramine. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with cholestyramine. Cholestyramine can decrease the intestinal absorption of fat-soluble vitamins like calcifediol.
Chromium: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Clarithromycin: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with clarithromycin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with clarithromycin. Clarithromycin, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Colestipol: (Moderate) Separate administration of calcifediol by 1 hour before or 4 hours after a colestipol dose to limit effects on oral absorption. Because it sequesters bile acids, colestipol may interfere with normal fat absorption and thus may reduce absorption of fat-soluble vitamins like calcifediol.
Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ritonavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ritonavir. Ritonavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Digoxin: (Moderate) Monitor serum calcium and patients for signs of digitalis toxicity in patients receiving calcifediol and digoxin concurrently. Monitor more frequently when initiating or adjusting the dose of calcifediol. Hypercalemia of any cause, including calcifediol therapy, increases the risk of digitalis toxicity.
Dihydrotachysterol: (Major) Withhold calcifediol treatment when using other vitamin D analogs, like dihydrotachysterol, due to the risk of additive toxicity including hypercalcemia, hypercalciuria, and hyperphosphatemia.
Doxercalciferol: (Major) Withhold calcifediol treatment when using other vitamin D analogs, like doxercalciferol, due to the risk of additive toxicity including hypercalcemia, hypercalciuria, and hyperphosphatemia.
Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Fosphenytoin: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with fosphenytoin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with fosphenytoin. Fosphenytoin stimulates microsomal hydroxylation and reduces the half-life of calcifediol. In rare cases, this has caused anticonvulsant-induced rickets and osteomalacia.
Hetastarch; Dextrose; Electrolytes: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts. (Moderate) Magnesium-containing drug products should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, the combined use of vitamin D analogs and magnesium-containing drug products should be avoided, if possible, in patients with chronic renal failure.
Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Ibritumomab Tiuxetan: (Major) High intake of phosphates concomitantly with vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Itraconazole: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with itraconazole. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with itraconazole. Itraconazole, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Ketoconazole: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ketoconazole. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ketoconazole. Ketoconazole, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with clarithromycin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with clarithromycin. Clarithromycin, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Levoketoconazole: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ketoconazole. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ketoconazole. Ketoconazole, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Lopinavir; Ritonavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ritonavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ritonavir. Ritonavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Magnesium Citrate: (Moderate) Magnesium-containing drug products, such as magnesium citrate, should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, the combined use of vitamin D analogs and magnesium-containing drug products should be avoided, if possible, in patients with chronic renal failure.
Magnesium Hydroxide: (Moderate) Magnesium-containing antacids, such as magnesium hydroxide, should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, concomitant use should be avoided, if possible, in patients with chronic renal failure.
Magnesium Salts: (Moderate) Magnesium-containing drug products should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, the combined use of vitamin D analogs and magnesium-containing drug products should be avoided, if possible, in patients with chronic renal failure.
Magnesium: (Moderate) Magnesium-containing drug products should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, the combined use of vitamin D analogs and magnesium-containing drug products should be avoided, if possible, in patients with chronic renal failure.
Methyclothiazide: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Metolazone: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Mineral Oil: (Moderate) Separate administration of oral vitamin D analogs by 1 hour before or 4 to 6 hours after mineral oil to limit effects on absorption and availability of the vitamin D analog. Absorption of fat-soluble vitamins may be decreased with concomitant administration of mineral oil. The bioavailability of orally administered vitamin D analogs may also be decreased.
Nefazodone: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with nefazodone. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with nefazodone. Nefazodone, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Nelfinavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with nelfinavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with nelfinavir. Nelfinavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Nirmatrelvir; Ritonavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ritonavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ritonavir. Ritonavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ritonavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ritonavir. Ritonavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Orlistat: (Moderate) Orlistat reduced the absorption of fat-soluble vitamins absorption during clinical trials. The bioavailability of orally administered vitamin D analogs may also be decreased. In patients receiving orally-administered vitamin D analogs along with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamin analogs be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Paricalcitol: (Major) Withhold calcifediol treatment when using other vitamin D analogs, like paricalcitol, due to the risk of additive toxicity including hypercalcemia, hypercalciuria, and hyperphosphatemia.
Phenytoin: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with phenytoin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with phenytoin. Phenytoin stimulates microsomal hydroxylation and reduces the half-life of calcifediol. In rare cases, this has caused anticonvulsant-induced rickets and osteomalacia.
Phosphorated Carbohydrate Solution: (Major) High intake of phosphates concomitantly with vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Phosphorus: (Major) High intake of phosphates concomitantly with vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Polycarbophil: (Moderate) The concurrent use of vitamin D analogs, like calcifediol with calcium polycarbophil may contribute to vitamin D-induced hypercalcemia. Each 625 mg of calcium polycarbophil contains a substantial amount of calcium (approximately 125 mg).
Potassium Phosphate: (Major) High intake of phosphates concomitantly with vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Potassium Phosphate; Sodium Phosphate: (Major) High intake of phosphates concomitantly with vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Pyridoxine, Vitamin B6: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with calcium salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and high doses of calcium-containing salts.
Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Ritonavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with ritonavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with ritonavir. Ritonavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Saquinavir: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with saquinavir. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with saquinavir. Saquinavir, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Sodium Sulfate; Magnesium Sulfate; Potassium Chloride: (Moderate) Magnesium-containing drug products should be used cautiously in patients receiving vitamin D analogs. Because vitamin D analogs can increase serum magnesium concentrations, the combined use of vitamin D analogs and magnesium-containing drug products should be avoided, if possible, in patients with chronic renal failure.
Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Telithromycin: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with telithromycin. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with telithromycin. Telithromycin, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.
Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Thiazide diuretics: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Dose adjustment of vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Voriconazole: (Moderate) Dose adjustment of calcifediol may be necessary during coadministration with voriconazole. Additionally, serum 25-hydroxyvitamin D, intact PTH, and calcium concentrations should be closely monitored if a patient initiates or discontinues therapy with voriconazole. Voriconazole, which is a cytochrome P450 inhibitor, may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) and may alter serum concentrations of calcifediol.