INTRANASAL AZELASTINE - A REVIEW OF ITS EFFICACY IN THE MANAGEMENT OFALLERGIC RHINITIS

Azelastine, a phthalazinone compound, is a second generation histamine H-1 receptor antagonist which has shown clinical efficacy in relievin g the symptoms of allergic rhinitis when administered as either an ora l or intranasal formulation. It is thought to improve both the early a nd late phase symptoms of rhinitis through a combination of antihistam inic, antiallergic and anti-inflammatory mechanisms. Symptom improveme nts are evident as early as 30 minutes after intranasal administration of azelastine [2 puffs per nostril (0.56 mg)] and are apparent for up to 12 hours in patients with seasonal allergic rhinitis (SAR). The ef fect on nasal blockage is variable: in some studies objective and/or s ubjective assessment showed a reduction in blockage, whereas in other studies there was no improvement. Intranasal azelastine 1 puff per nos tril twice daily is generally as effective as standard doses of other antihistamine agents including intranasal levocabastine and oral cetir izine, ebastine, loratadine and terfenadine at reducing the overall sy mptoms of rhinitis. The relative efficacies of azelostine and intranas al corticosteroids (beclomethasone and budesonide) remain unclear. How ever, overall, the corticosteroids tended to improve rhinitis symptoms to a greater extent than the antihistamine. Azelastine was well toler ated in clinical trials and postmarketing surveys. The most frequently reported adverse events were bitter taste, application site irritatio n and rhinitis. The incidence of sedation did not differ significantly between azelastine and placebo recipients and a preliminary report sh owed cardiovascular parameters were not significantly altered in patie nts with perennial allergic rhinitis (PAR). Conclusion: Twice-daily in tranasal azelastine offers on effective and well tolerated alternative to other antihistamine agents currently recommended for the symptomat ic relief of mild to severe SAR and PAR in adults and children (aged g reater than or equal to 12 years in the US; aged greater than or equal to 6 years in some European countries including the UK). The rapid on set, confined topical activity and reduced sedation demonstrated by th e intranasal formulation of azelastine may offer an advantage over oth er antihistamine agents, although this has yet to be confirmed.