A comparison of acrivastine versus clemastine and placebo in the treatment of patients with chronic idiopathic urticaria.

Twenty patients of mean age 41.3 years, with a diagnosis of chronic idiopathic urticaria were assessed in a fully randomized, double-blind, crossover study to investigate the efficacy of acrivastine at two doses (8 mg and 4 mg) versus 1 mg clemastine and placebo, given three times per day. All active preparations were found to be effective, and significantly better than placebo, in controlling the signs and symptoms of urticaria. There was a higher incidence of sedation with clemastine than with either acrivastine or placebo, although this difference did not achieve statistical significance in this small study.