Use of histamine2-antagonists for the treatment of verruca vulgaris

OBJECTIVE: To review the evidence for histamine(2) (H-2)-antagonists in the treatment of common warts. DATA SOURCES: Relevant publications were identified through a systematic search of PubMed English-language literature using the MeSH terms and key words cimetidine, ranitidine, famotidine, nizatidine, histamine H-2-antagonists, and warts. Additional articles were identified using the same key words in the Cochrane Database and International Pharmaceutical Abstracts. Systematic searches were conducted through January 2007. In addition, pertinent references from identified articles were reviewed. STUDY SELECTION AND DATA EXTRACTION: The literature search retrieved 21 relevant citations, excluding review articles. Five open-label studies and 7 randomized controlled clinical trials were evaluated. Cimetidine was the focus of 11 studies, and ranitidine was evaluated in 1 study. No data regarding the other H2 antagonists were found. The other retrieved citations were not evaluated due to their design (case reports or case series) and/or focus on specific wart subtypes, not common warts. DATA SYNTHESIS: The use of H-2-antagonists in the treatment of common warts is not associated with significant improvements in resolution rates. Open-label studies were promising with an estimated 48-81% response rate. However, randomized controlled trials have failed to show significant efficacy when cimetidine was compared with placebo or topical agents, and ranitidine has never been evaluated in a randomized controlled trial. Adverse effects, specifically gastrointestinal complaints, were documented. Efficacy may have been limited by inadequate dosing in some of the trials. The studies were limited by the small sample size and lack of power in a number of the trials, as well as the documented spontaneous resolution rate for warts. CONCLUSIONS: Several open-label trials evaluating the use of H-2-antagonists for verruca vulgaris reported high response rates, but these results have not been corroborated by more rigorous clinical trials. Current data do not support the use of H-2-antagonists for the treatment of common warts.