Relative efficacy and safety of loratadine, hydroxyzine, and placebo in chronic idiopathic urticaria and atopic dermatitis

Abstract

The subjects of this double-blind study were 59 patients with chronic idiopathic urticaria or atopic dermatitis randomly assigned to receive 10 mg of loratadine once daily and placebo twice daily (n = 20), 25 mg of hydroxyzine thrice daily (n = 20), or placebo thrice daily (n = 19). The patients (15 men, 44 women) were aged 18 to 65 years. Among the 18 patients with urticaria and 41 with atopic dermatitis, daily symptom scores decreased 43% and 57% in those receiving loratadine, 47% and 38% in those receiving hydroxyzine, and 0% and 33% in the placebo patients. The difference between the treated and placebo patients was significant among the urticaria patients. According to a global evaluation of treatment effects, more treated than placebo patients reported marked or complete symptom relief; among the patients with atopic dermatitis, the difference was significant between the loratadine and placebo patients. Somnolence or sedation during treatment was reported by one of the patients receiving loratadine, by eight of the hydroxyzine patients, and by two of the placebo patients; the difference between the loratadine and hydroxyzine patients was significant. It was concluded that loratadine is as effective as hydroxyzine in the treatment of urticaria and demonstrates a significant antipruritic effect in atopic dermatitis, but does not have the central nervous system effects of hydroxyzine.