Safety and efficacy of cetirizine versus cetirizine plus ranitidine in chronic urticaria: Double-blind randomized placebo-controlled study

Background: First-line treatment for chronic urticaria is H1 non-sedating antihistamines. When these fail, guidelines recommend combination with H2 antihistamines. Aim: We conducted a randomized, double-blind, placebo-controlled trial. Methods: Thirty-two patients with chronic urticaria were included. Group A (16 subjects) treated with cetirizine plus ranitidine and Group B (16 subjects) with cetirizine plus placebo, both for 30 days. Efficacy measures were Urticaria Activity Score (UAS), Chronic Urticaria Quality of Life Questionnaire (CU-Q(2)oL) and time of symptom remission, safety measures were clinical and laboratory effects. Results: Complete remission was obtained in ten patients (62.5%) from Group A and seven patients (44%) from Group B (p = 0.28). The UAS in Group A was 1.53 +/- 2.09 versus Group B 2.06 +/- 1.34 (p = 0.20). The CU-Q(2)oL in Group A was 12.93 +/- 19.20 versus Group B 12.68 +/- 10.30 (p = 0.20). At the end of treatment, 13 patients (81%) from Group A and 14 patients (87.5%) from Group B had some type of adverse effect (p = 1.0). Conclusions: Combination of cetirizine with ranitidine was not more effective than cetirizine alone in chronic urticaria. Both treatments resulted equally safe; however, our main limitation is the small sample size.