Ranitidine does not affect psoriasis: a multicenter, double-blind, placebo-controlled study.

Background: Data from open studies suggest that ranitidine has a beneficial effect on psoriasis and is well tolerated.

Objective: Our purpose was to determine the effectiveness of ranitidine in a 24-week, multicenter, double-blind, placebo-controlled, dose-comparing study of 201 patients with psoriasis.

Methods: Patients with moderate to severe psoriasis who had stopped systemic antipsoriatic therapy, including PUVA and UVB, for at least 10 weeks were included. After a washout period of 2 weeks, patients were randomly allocated to use either ranitidine, 150 mg twice a day; ranitidine, 300 mg twice a day; or placebo for up to 24 weeks. Assessment with the Psoriasis Area and Severity Index was performed at weeks 3, 6, 9, 12, 18, and 24 after randomization. Reduction of the Psoriasis Area and Severity Index score by 70% at the completion of the study was considered a treatment success.

Results: The success rates at week 24 in the 300 mg, 600 mg, and placebo groups were 11%, 5%, and 12%, respectively. No significant differences were observed between the three treatment groups at any stage of the study.

Conclusion: This study provides strong evidence that ranitidine does not affect the skin disease in patients with psoriasis.