Long-term treatment of ulcerative colitis with ciprofloxacin: a prospective, double-blind, placebo-controlled study

Although bacterial bowel flora may be one of the contributing factors in the pathogenesis of chronic mucosal inflammation, antibiotic treatment has no established role in ulcerative colitis. The aim of the study was to evaluate the role of ciprofloxacin in the induction and maintenance of remission in ulcerative colitis in patients responding poorly to conventional therapy with steroids and mesalamine.

Ciprofloxacin (n = 38; 500-750 mg twice a day) or placebo (n = 45) was administered for 6 months in a double-blind, randomized study with a high but decreasing dose of prednisone and maintenance treatment with mesalamine including follow-up for the next 6 months. Clinical assessment and colonoscopic evaluation were performed at 0, 3, 6, and 12 months. Treatment failure, the primary end point, was defined as both symptomatic and endoscopic failure to respond.

During the first 6 months, the treatment-failure rate was 21% in the ciprofloxacin-treated group and 44% in the placebo group (P = 0.02). Endoscopic and histological findings were used as secondary end points and showed better results in the ciprofloxacin group at 3 months but not at 6 months.

Addition of a 6-month ciprofloxacin treatment for ulcerative colitis improved the results of conventional therapy with mesalamine and prednisone.