Drug information of Epinastine


Epinastine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Epinastine ophthalmic (for the eyes) is used to prevent itching of the eyes caused by allergies. Epinastine ophthalmic should not be used to treat eye irritation or discomfort caused by wearing contact lenses.

Mechanism of effect

Epinastine has a multiaction effect that inhibits the allergic response in 3 ways: 1. stabilizes mast cells by preventing mast cell degranulation to control the allergic response, 2. prevents histamine binding to both the H1- and H2-receptors to stop itching and provide lasting protection, and 3.

prevents the release of proinflammatory chemical mediators from the blood vessel to halt progression of the allergic response.


Epinastine is an antihistamine and an inhibitor of histamine release from the mast cell for topical administration to the eyes. Epinastine is indicated for the prevention of itching associated with allergic conjunctivitis. Epinastine is a topically active, direct H1-receptor antagonist and an inhibitor of the release of histamine from the mast cell.

Epinastine is selective for the histamine H1-receptor and has affinity for the histamine H2 receptor. Epinastine also possesses affinity for the a1-, a2-, and 5-HT2 -receptors. Epinastine does not penetrate the blood/brain barrier and, therefore, is not expected to induce side effects of the central nervous system.


  • Absorption: The absolute bioavailability of epinastine is about 40%.
  • Volume of distribution: Not Available
  • Protein binding: 64%.
  • Metabolism: Mainly excreted unchanged, less than 10% metabolized.
  • Route of elimination: Epinastine is mainly excreted unchanged. The renal elimination is mainly via active tubular secretion.
  • Half life: 12 hours.

Drug indications

itchy eyes

Allergic Conjunctivitis: Prevention of ocular itching associated with allergic conjunctivitis.


Pediatric Patients

Allergic Conjunctivitis


Children ≥3 years of age: 1 drop of a 0.05% solution in each eye twice daily for up to 8 weeks.

Continue therapy throughout period of exposure (i.e., until pollen season is over or until exposure to offending allergen is terminated), even in absence of symptoms.


Allergic Conjunctivitis


1 drop of a 0.05% solution in each eye twice daily for up to 8 weeks.

Continue therapy throughout period of exposure (i.e., until pollen season is over or until exposure to offending allergen is terminated), even in absence of symptoms.

Drug contraindications

severe hypersensitivity reactions

Known hypersensitivity to epinastine or any ingredient in the formulation.

Side effects

Sinusitis , Headache , rhinitis , itchy eyes


No formal drug interaction studies to date.


Safety and efficacy not established in children <3 years of age.

  • Bacterial keratitis: Inadvertent contamination of multiple-dose ophthalmic solutions has caused bacterial keratitis.
  • Contact lens wearers: Contains benzalkonium chloride which may be absorbed by contact lenses; remove contact lenses prior to use and wait 10 minutes before reinserting.
  • Appropriate use: For topical ophthalmic use only. Not for the treatment of contact lens irritation; do not wear contact lenses if eye is red.

Points of recommendation

To make sure this medicine is safe for you, tell your doctor if you have:

  • If you have an allergy to epinastine or any other part of epinastine.
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.

Do not use epinastine to treat contact lens irritation.

Do not wear contact lenses if your eyes are red.

Use as you have been told, even if your signs get better.

Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using epinastine while you are pregnant.

Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

Take out contact lenses before using epinastine. Lenses may be put back in 10 minutes after epinastine is given. Do not put contacts back in if your eyes are irritated or infected.

Wash hands before and after use.

Do not touch the container tip to the eye, lid, or other skin.

Tilt your head back and drop drug into the eye.

After use, keep your eyes closed. Put pressure on the inside corner of the eye. Do this for 1 to 2 minutes. This keeps the drug in your eye.

Do not use if solution changes color.

Use a missed dose as soon as you think about it. If it is close to the time for your next dose, skip the missed dose and go back to your normal time. Do not use 2 doses or extra doses.

Pregnancy level


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