Pharmacodynamic evaluation of azelastine in subjects with asthma

A broad antiallergic compound called azelastine was studied pharmacodynamically in 34 subjects to correlate bronchodilator effect with blood levels of azelastine and desmethyl azelastine, its major metabolic product in man. Despite azelastine and desmethyl azelastine blood levels that were proportionate to the dosage range, the bronchodilator effect as measured by FEV 1 and forced expiratory flow rate between 25% and 75% of FVC was proportionately greater with 4 mg of azelastine during the 8-hour study period than the anticipated bronchodilator response with the 8 and 16 mg doses. Azelastine, already proven effective in allergic rhinitis, has a bronchodilator effect at doses that do not produce intolerable side effects.