[9] It is a second-generation antihistamine and works by blocking the release of a number of inflammatory mediators including histamine.

[17][18][19] Bitter taste, headache, nasal burning and somnolence are the most frequently reported adverse events.

US prescribing recommendations warn against the concurrent use of alcohol and/or other central nervous system depressants, but to date there have been no studies to assess the effects of azelastine nasal spray on the CNS in humans[needs update?].

[22] The problem of bitter taste may also be reduced by correct application of the nasal spray (i.e. slightly tipping the head forward and not inhaling the medication too deeply), or alternatively using the azelastine/sucralose formulation.

[23] In addition, anosmia (loss in the ability to smell) can occur with nasal spray antihistamines (including both formulations of azelastine).

[4] The elimination half life, steady-state volume of distribution and plasma clearance are 22 h, 14.5 L/kg and 0.5 L/h/kg respectively (based on intravenous and oral administration data).