Topical metronidazole treatment in pouchitis

Patients with pouchitis usually respond to oral metronidazole treatment, but side effects of the treatment are common. Eleven patients with pouchitis were given local treatment by instillation of metronidazole in doses of 40-160 mg daily into the reservoir. The effects of the treatment on the bacterial flora and short-chain fatty acids in reservoir contents, morphology of the ileal mucosa, and serum concentrations of metronidazole were studied. All patients responded to local administration of metronidazole. Three patients with chronic pouchitis remained well for 6 months, 3 years, and 4 years, taking 40 mg metronidazole daily. Three patients had one single treatment course, and four had repeated courses when they had recurrences. In one patient a continent reservoir had to be removed owing to a persistent ulcer causing chronic blood loss. The bacterial flora of reservoir contents showed no significant differences between patients with and without pouchitis. The number of anaerobic microorganisms and the concentration of short-chain fatty acids were reduced after metronidazole treatment. Serum concentrations of metronidazole were very low, and no patients experienced any side effects of the treatment. In conclusion, topical application of small doses of metronidazole relieved symptoms in most cases of pouchitis and was well tolerated, even as long-term treatment.