A study of the clinical efficacy of azelastine in patients with extrinsic asthma, and its effect on airway responsiveness.

Abstract

1 The effect of 4.4 mg azelastine administered orally on airway responsiveness, skin prick testing, daily peak expiratory flow rates and symptoms of asthma was compared with placebo in a 7 week double-blind, parallel group study of 24 patients with extrinsic asthma. The study was in two parts: a 2 week assessment period, during which all patients received placebo tablets but recorded daily peak flow rates (PEFRs) and symptoms, preceding the 7 week double-blind comparison. 2 Azelastine, 4.4 mg, significantly decreased airway responsiveness to histamine compared with placebo both after a single dose (P < 0.001), and following 7 weeks continuous treatment (P < 0.02). Airway responsiveness to methacholine was not altered by administration of azelastine compared with placebo. 3 Skin prick test weal diameters to both allergen and histamine were significantly reduced after both a single dose and following 7 weeks continuous therapy treatment with azelastine. 4 There was a significant improvement in both the mean of the morning and the evening peak flow rates recorded during the last week compared with the first week of the study in the group receiving 4.4 mg of azelastine twice daily compared with placebo. Scores for wheeze were significantly reduced during the final 3 weeks of the study in patients receiving azelastine compared both with those receiving placebo and with the first week of the study (P < 0.05, P < 0.01). Consumption of inhaled bronchodilators fell significantly during the study in the group receiving azelastine therapy (P < 0.05); no such fall occurred in the placebo treated patients. 5 A bitter metallic taste was reported by 58% of patients who received azelastine therapy.

Effects of antihistamines in adult asthma: a meta-analysis of clinical trials

“…By contrast, the use of "rescue" bronchodilators may be more easily compared between studies. This [29]; terfenadine [22,32,36]; azelastine [33,37]; picumast [35]; permirolast [19]; loratidine [20]; cetirizine [24].…”

Effects of H1‐receptor blockade with terfenadine in nocturnal asthma.

“…Cookson (1987) reported a 30% increase in expiratory flow at 25% of vital capacity in seven atopic asthmatics with normal lung function 2 h after terfenadine 120 mg. Two outpatient studies have examined the effects of H1-receptor blockade on morning and evening PEFR measurements in mild extrinsic asthmatics who did not demonstrate a significant diurnal variation in PEFR; both showed an improvement in morning and evening PEFR (Gould et al, 1988;Taytard et al, 1987).…”

“…Correspondence: Dr C. Teale, Pulmonary Function Laboratory, Killingbeck Hospital, York Road, Leeds, LS14 6UQ (Gould et al, 1988;Taytard et al, 1987).…”

Histamine and asthma: an appraisal based on specific H1‐receptor antagonism

“…The failure to identify bronchodilatation with continuous therapy with azelastine. despite bronchodilatation on first dose administration [72]. would not bo inconsistent with this concept and suggests the possibility of airway tachyphylaxis to the bronchodilator actions of H|-antihistamines.…”