A Comprehensive Monograph on Azelastine (DB00972)

Executive Summary

Azelastine is a second-generation, phthalazinone-derivative antihistamine distinguished by a uniquely comprehensive pharmacological profile that extends beyond simple histamine receptor blockade.[1] Its primary clinical utility stems from a multi-modal mechanism of action that includes potent and selective histamine H1-receptor antagonism, stabilization of mast cells to prevent mediator release, and broad anti-inflammatory effects.[1] These properties make it a highly effective agent for the management of allergic rhinitis (seasonal and perennial), non-allergic vasomotor rhinitis, and allergic conjunctivitis, for which it is available in intranasal and ophthalmic formulations.[1] A key clinical advantage of Azelastine is its rapid onset of action, with intranasal formulations providing symptom relief within 15 minutes, a significant improvement over most oral antihistamines.[1]

The drug is generally well-tolerated, with the most common adverse effects being a transient bitter taste and the potential for somnolence. A critical safety consideration is the warning against concurrent use with alcohol or other central nervous system (CNS) depressants due to the risk of additive impairment.[3] Azelastine's long history of clinical use, beginning with its initial U.S. Food and Drug Administration (FDA) approval in 1996, culminated in the landmark prescription-to-over-the-counter (Rx-to-OTC) switch of its 0.15% nasal spray formulation in 2021, a testament to its robust safety and efficacy record.[2]