Efficacy of mizolastine, a new antihistamine, compared with placebo in the treatment of chronic idiopathic urticaria.

A two-centre, double-blind, randomized, placebo (P)-controlled, parallel-group study was conducted in the UK to examine the efficacy and safety of mizolastine (M), a new H1-receptor antagonist, as a once-daily 10-mg dose in chronic idiopathic urticaria. Fifty-six outpatients (M: n = 28; P: n = 28) with a mean age of 38 +/- 15 years, a duration of disease of more than 3 years, and symptoms of urticaria at least twice a week in the absence of treatment were recruited. After a single-blind placebo run-in period, patients were allocated to one of two treatment groups and were evaluated after 7 and 28 days. The main characteristics (age, duration of disease, number of urticarial episodes, and total score) of the two groups were comparable at inclusion. Mizolastine was shown to improve the urticaria symptoms: at the end of the study, mizolastine produced a significantly greater decrease in the global symptom score comprising itch, wheals, and erythema (M: 2.1 +/- 2.1 vs P: 0.4 +/- 2.0; P = 0.002). The patient-rated global discomfort from symptoms measured by visual analog scale was significantly improved with mizolastine (M: 31.4 +/- 36.7) compared to placebo (P: 5.4 +/- 27.6; P = 0.003), with respectively more M responders (74.1%) than P responders (28.6%, P = 0.001), a responder being a patient with a > or = 50% decrease in VAS. Premature dropouts due to lack of efficacy and loss to follow-up mainly occurred at the first evaluation (day 7) and were more often observed in patients in the placebo group (n = 17) than in the mizolastine group (n = 8) (P = 0.031). No serious adverse events were recorded. Somnolence was reported in two mizolastine patients, one of whom discontinued the study. Thus, mizolastine may be considered a new treatment option for the symptoms of chronic urticaria.