Randomized clinical trial of metronidazole ointment versus placebo in perianal Crohn's disease.

Author(s): Maeda Y, Ng SC, Durdey P, Burt C, Torkington J, Rao PK, Mayberry J, Moshkovska T, Stone CD, Carapeti E, Vaizey CJ, Topical Metronidazole in Perianal Crohn's Study Group

Affiliation(s): Physiology Unit, St Mark's Hospital, Harrow, UK. yazmaeda@googlemail.com

Publication date & source: 2010-09, Br J Surg., 97(9):1340-7.

Publication type: Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

BACKGROUND: The potential for metronidazole 10 per cent ointment to exert therapeutic benefit in perianal Crohn's disease, while minimizing the adverse effects found with oral metronidazole, was evaluated in a randomized placebo-controlled study. METHODS: Subjects with perianal Crohn's disease were randomized to metronidazole 10 per cent ointment, 0.7 g applied perianally three times daily, or placebo ointment. The Perianal Crohn's Disease Activity Index (PCDAI) was scored at baseline and after 4 weeks of treatment. Perianal pain was assessed on a visual analogue scale. RESULTS: Seventy-four subjects (33 metronidazole, 41 placebo) were evaluated. The mean(s.e.m.) reduction in PCDAI score at 4 weeks was 2.4(0.5) in the metronidazole group and 2.2(0.4) in the placebo group (P = 0.660). More subjects in the metronidazole group than the placebo group showed a reduction in PCDAI score of at least 5 points (10 of 27 versus 4 of 34; P = 0.031). Perianal discharge was reduced significantly in metronidazole-treated subjects (P = 0.012). A greater reduction in perianal pain was seen in the metronidazole group, which approached statistical significance (P = 0.059). No serious adverse events were reported. CONCLUSION: Metronidazole 10 per cent ointment was not effective in the reduction of PDCAI score, but some secondary outcomes showed improvement suggestive of a treatment effect. It is well tolerated, with minimal adverse effects, and has potential as treatment for pain and discharge associated with perianal Crohn's disease. Registration number: NCT00509639 (http://www.clinicaltrials.gov). Copyright 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.