CLASSES

Ocular Anti-Allergics, Antihistamines

DEA CLASS

Rx

DESCRIPTION

Topical ophthalmic H1-antagonist; inhibitor of mast cell histamine release; prevents ocular pruritus associated with allegic conjunctivitis.

COMMON BRAND NAMES

Elestat

HOW SUPPLIED

Elestat/Epinastine/Epinastine Hydrochloride Ophthalmic Sol: 0.05%

DOSAGE & INDICATIONS

MAXIMUM DOSAGE

2 drops/day ophthalmic solution in each affected eye.

2 drops/day ophthalmic solution in each affected eye.

2 drops/day ophthalmic solution in each affected eye.

>= 2 years: 2 drops/day ophthalmic solution in each affected eye.
< 2 years: Safety and efficacy have not been established.

DOSING CONSIDERATIONS

Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.

ADMINISTRATION

For topical application to the eye only.
Wash hands before and after use. Tilt the head back slightly and pull the lower eyelid down with the index finger. Squeeze the prescribed number of drops into the conjunctival sac and gently close eyes for 1—2 minutes. Do not blink.
Care should be taken to avoid contamination. Do not touch the tip of the dropper to the eye, fingertips, or other surface.
Patients should wait at least ten minutes after instilling the ophthalmic solution before they insert their contact lenses.
Do not share ophthalmic drops between patients.

STORAGE

Elestat:
- Store between 68 to 77 degrees F, excursions permitted 59 to 86 degrees F

CONTRAINDICATIONS / PRECAUTIONS

No overall differences in safety or effectiveness have been observed between elderly and younger patients receiving epinastine ophthalmic solution.

Epinastine is contraindicated for use in patients with a known history of hypersensitivity to epinastine or other product ingredients. Epinastine ophthalmic solution is formulated with the preservative benzalkonium chloride 0.01%, which may be absorbed by soft contact lenses. Users of soft contact lenses should not administer epinastine while wearing contact lenses. Contact lenses may be inserted 10 minutes after instilling the drug. Do not use epinastine to treat contact lens related ocular irritation.

Epinastine is classified as pregnancy risk category C. Epinastine reduced pup body weight gain in rats following doses that exceeded 90,000 times the MROHD. No adequate and well-controlled studies in pregnant women have been performed. The use of epinastine in pregnant women is only justified if the benefits outweigh the possible risks to the fetus.

According to the manufacturer, it is not known whether epinastine is excreted into human milk and caution should be exercised when epinastine is administered to women who are breast-feeding. However, the systemic absorption of epinastine is very low after ophthalmic administration ; therefore, clinically significant amounts of the drug would not be expected in breast-milk. To further minimize the amount of drug that reaches the systemic circulation and breast milk, apply pressure over the tear duct by the corner of the eye for 1 minute after ophthalmic administration. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.

ADVERSE REACTIONS

hyperemia / Delayed / 1.0-10.0

ocular irritation / Rapid / 1.0-10.0
ocular pruritus / Rapid / 1.0-10.0
infection / Delayed / 10.0-10.0
headache / Early / 1.0-3.0
pharyngitis / Delayed / 1.0-3.0
sinusitis / Delayed / 1.0-3.0
rhinitis / Early / 1.0-3.0
cough / Delayed / 1.0-3.0
lacrimation / Early / Incidence not known

DRUG INTERACTIONS

There are no drug interactions associated with Epinastine products.

PREGNANCY AND LACTATION

Epinastine is classified as pregnancy risk category C. Epinastine reduced pup body weight gain in rats following doses that exceeded 90,000 times the MROHD. No adequate and well-controlled studies in pregnant women have been performed. The use of epinastine in pregnant women is only justified if the benefits outweigh the possible risks to the fetus.

According to the manufacturer, it is not known whether epinastine is excreted into human milk and caution should be exercised when epinastine is administered to women who are breast-feeding. However, the systemic absorption of epinastine is very low after ophthalmic administration ; therefore, clinically significant amounts of the drug would not be expected in breast-milk. To further minimize the amount of drug that reaches the systemic circulation and breast milk, apply pressure over the tear duct by the corner of the eye for 1 minute after ophthalmic administration. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.

MECHANISM OF ACTION

Epinastine is a topically active, direct H1-receptor antagonist. Epinastine also inhibits histamine release from mast cells. Epinastine is a relatively selective H1-antagonist which has some affinity for the H2-receptor. Following topical ocular administration, epinastine blocks H1-receptors and inhibits histamine-stimulated vascular permeability in the conjunctiva. As a result, emedastine relieves the ocular pruritus associated with allergic conjunctivitis. Epinastine also has affinity for the alpha-1, alpha-2, and 5-HT2 receptors. Epinastine does not cross the blood brain barrier, and therefore is not expected to induce CNS side effects.

PHARMACOKINETICS

Epinastine is administered topically to the eye. Epinastine is 64% bound to plasma proteins. Approximately 55% of an intravenous dose is recovered in the urine as unchanged drug, with about 30% recovered in the feces. Less than 10% is metabolized. Renal elimination occurs primarily via active tubular secretion. The plasma elimination half-life for epinastine is about 12 hours.