Review of the pharmacology, clinical efficacy, and safety of azelastine hydrochloride

Rhinitis is one of the most common diseases in the general population. Although it is not a life-threatening condition, rhinitis can cause significant discomfort and, therefore, negatively impact quality of life. Several treatment options are available; however, optimal relief of symptoms is difficult to achieve for most patients. Azelastine hydrochloride (Astelin) nasal spray is the only prescription intranasal antihistamine available in the USA, and is approved for treating symptoms of both seasonal allergic rhinitis and nonallergic vasomotor rhinitis. Oral formulations of azelastine are available outside the USA for use in seasonal and perennial allergic rhinitis, asthma and urticaria. Azelastine hydrochloride has demonstrated a favorable safety profile during approximately 20 years of clinical use.

Efficacy and safety of azelastine 0.15% nasal spray and azelastine 0.10% nasal spray in patients with seasonal allergic rhinitis

Azelastine is a second-generation antihistamine approved for treatment of allergic rhinitis. This randomized, double-blind, placebo- and active-controlled, parallel-group clinical trial evaluated the efficacy and safety of azelastine 0.15% and azelastine 0.10% nasal spray at a dosage of 2 sprays/nostril twice daily in patients with moderate-to-severe seasonal allergic rhinitis (SAR). In total, 526 patients were randomized 1:1:1 to treatment with 2 sprays/nostril twice daily of azelastine 0.15%, azelastine 0.10%, or placebo. The primary efficacy variable was change from baseline in 12-hour reflective Total Nasal Symptom Score (TNSS; A.M. and P.M. combined), consisting of nasal congestion, rhinorrhea, itchy nose, and sneezing. After 2 weeks, the mean improvement and percentage improvement in the 12-hour reflective TNSS were significant (p < 0.001) with azelastine 0.15% and azelastine 0.10% compared with placebo. In a retrospective analysis, there was a statistical difference (p = 0.047) in the mean improvement versus placebo in the 12-hour reflective TNSS with azelastine 0.15% compared with azelastine 0.10%. Onset of action with azelastine 0.15% was within 30 minutes. Bitter taste was the most common adverse event with both azelastine 0.15% and azelastine 0.10% (8.4% and 9.4% of patients, respectively). Somnolence was reported by 1.7% of patients treated with azelastine 0.15%, 0.6% of patients treated with azelastine 0.10%, and 0.6% of patients treated with placebo. Azelastine 0.15% nasal spray at 2 sprays/nostril twice daily significantly improved the nasal symptoms associated with SAR with an onset of action within 30 minutes and was well tolerated.