For the symptomatic treatment of seasonal allergic rhinitis and non-allergic rhinitis, as well as symptomatic relief of ocular itching associated with allergic conjunctivitis.
Azelastine competes with histamine for the H1-receptor sites on effector cells and acts as an antagonist by inhibiting the release of histamine and other mediators involved in the allergic response.
Absorption of azelastine following ocular administration was relatively low. Systemic bioavailability is approximately 40% after nasal administration.
Elimination half-life (based on intravenous and oral administration) is 22 hours. Elimination half-life of the active metabolite, desmethylazelastine, is 54 hours (after oral administration of azelastine).
Approximately 75% of an oral dose of radiolabeled azelastine hydrochloride was excreted in the feces with less than 10% as unchanged azelastine. Azelastine hydrochloride is oxidatively metabolized to the principal metabolite, N-desmethylazelastine, by the cytochrome P450 enzyme system.
* 14.5 L/kg
* 0.5 L/h/kg [symptomatic patients]