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


CONCLUSIONS
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.


BACKGROUND
NCT00509639 (http://www.clinicaltrials.gov).
Maeda
Y
Y
Physiology Unit, St Mark's Hospital, Harrow, UK. yazmaeda@googlemail.com
Ng
S C
SC
Durdey
P
P
Burt
C
C
Torkington
J
J
Rao
P Kumar Dhruva
PK
Mayberry
J
J
Moshkovska
T
T
Stone
C D
CD
Carapeti
E
E
Vaizey
C J
CJ
D000287:Administration, Topical; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001004:Anus Diseases / Q000188:drug therapy*; D003424:Crohn Disease / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage* / Q000009:adverse effects; D009824:Ointments; D010146:Pain / Q000517:prevention & control; D017060:Patient Satisfaction; D011788:Quality of Life; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D009824:Ointments; D008795:Metronidazole