Emedastine

Absorption

Ophthalmic use of emedastine usually does not produce measurable plasma concentrations.

Toxicity

Somnolence and malaise have been reported following daily oral administration.

The Uses of Emedastine

Antihistaminic, H1-receptor; asthma prophylactic; anti-allergic.

Indications

For the temporary relief of the signs and symptoms of allergic conjunctivitis.

Background

Emedastine is an antihistamine used in eye drops to treat allergic conjunctivitis.

Definition

ChEBI: 1-Methyl-1,4-diazepane in which the hydrogen attached to the nitrogen at position 4 is substituted by a 1-(2-ethoxyethyl)-1H-benzimidazol-2-yl group. A relatively selective histamine H1 antagonist, it is used as the ifumatate salt for allergic rhinitis, urticaria, and pruritic skin disorders, and in eyedrops for the symptomatic relief of allergic conjuntivitis.

brand name

Emadine (Alcon).

Pharmacokinetics

Emedastine is a relatively selective H1-receptor antagonist.

Clinical Use

Emedastine also is a newer antihistamine used topically in the eye for conjunctivitis. It has very high H1 receptor selectivity characteristics, and it is structurally related to the benzimidazoles, such as astemizole. Inhibition of mast cell release of inflammatory mediators has been noted.

Metabolism

Two primary metabolites, 5-hydroxyemedastine and 6-hydroxyemedastine, are excreted in the urine as both free and conjugated forms. Minor metabolites include the 5'-oxoanalogs of 5-hydroxyemedastine and 6-hydroxy-emedastine and the N-oxide.