Cetirizine versus hydroxyzine and placebo in chronic idiopathic urticaria.

OBJECTIVE

To compare the safety and efficacy of cetirizine with that of hydroxyzine and placebo in the treatment of chronic idiopathic urticaria.

DESIGN

A 4-week multicenter, randomized, double-blind, double-dummy, placebo-controlled safety and efficacy study.

SETTING

Patients were treated in a variety of allergy practice settings.

PATIENTS

The study population consisted of 188 patients who were at least 12 years of age, with symptomatic chronic idiopathic urticaria that had occurred episodically for at least 6 weeks.

INTERVENTIONS

Patients were given either cetirizine 10 mg once daily, hydroxyzine 25 mg tid, or placebo for 4 weeks.

MAIN OUTCOME MEASURES

Patients and investigators used a 4-point scale to evaluate symptoms of urticaria and adverse effects of treatment. Ratings were compared among those taking cetirizine, hydroxyzine, or placebo.

RESULTS

After 1 day of treatment, patients randomized to receive cetirizine 10 mg/d exhibited a reduction in the number of episodes of urticaria (and a reduction in pruritus) compared with patients who received hydroxyzine 25 mg tid and patients who received placebo (p = 0.002). The number of urticarial episodes in patients treated with hydroxyzine did not reach significance until day 2 (p = 0.001). Compared with patients who received placebo, patients who received cetirizine and those who received hydroxyzine showed reductions during weeks 1, 2, and 3 and at end-point analysis in the number and size of lesions and in the severity of pruritus (p < 0.04). Patient and physician evaluations at the end of week 4 revealed an improvement in urticarial symptoms for the hydroxyzine and cetirizine groups compared with the placebo group (p < 0.001). Four patients in the hydroxyzine group, 1 patient in the cetirizine group, and 1 patient in the placebo group discontinued the study because of sedation. No patient withdrew because of lack of efficacy.

CONCLUSIONS

Cetirizine 10 mg once daily was equivalent to hydroxyzine 25 mg tid in controlling the symptoms of patients with chronic urticaria, as assessed by patient and investigator evaluations.