A Clinical Comparison of Cetirizine Versus Astemizole in Perennial Allergic Rhinitis

Abstract

The rapidity of action, efficacy and tolerability of cetirizine and astemizole, 2 second generation H1-receptor antagonists, were investigated in patients in a 1-month double-blind parallel randomised study. 59 patients known to be perennial rhinitis sufferers completed the study; 30 patients received a regimen of cetirizine 10mg and 29 received astemizole 10mg. Symptoms were assessed at days 1, 14 and 28 by the investigator, and were scored daily by the patients. In addition, the H1 antagonist activity was measured using several allergens, intradermal skin tests and a nasal histamine sensitivity test (NHST). The time to relief of symptoms was recorded by the patients in minutes, hours or days. A 10cm visual analogue scale was used for the assessment of the patients’ general condition. The results showed a faster relief of symptoms and a better effect on rhinorrhoea with cetirizine (p < 0.03). NHST was significantly improved with both astemizole and cetirizine compared with baseline data, but there was no significant difference between astemizole and cetirizine. Patients’ reports also indicated that cetirizine relieved the symptoms faster than astemizole, at mean times of 0.58 and 13.6 hours, respectively (p < 0.01). Both products were similarly well tolerated, with mild and transient drowsiness affecting 4 of 30 patients taking cetirizine and 4 of 29 patients taking astemizole.