MI Johnson, D Merrilees, WA Robson, T Lennon, J Masters, KE Orr, JNS Matthews, DE Neal
OBJECTIVE: To report a large prospective, pragmatic, double-blind randomized controlled trial to determine whether oral prophylactic antibiotics reduce the risk of bacteriuria after flexible cystoscopy (FC), as up to 10% of patients develop urinary infection afterwards, with significant morbidity and costs for health services. PATIENTS AND METHODS: In all, 2481 patients were recruited into a three-arm placebo controlled trial and 2083 completed it. Patients were randomly assigned to one of three treatments; (i) placebo; (ii) one oral dose of trimethoprim (200 mg); or (iii) one oral dose of ciprofloxacin (500 mg), each administered 1 h before a FC under local anaesthetic. A mid-stream urine specimen was taken before and 5 days after FC; significant bacteriuria was defined as a pure growth of >10(5) colony-forming units/mL. RESULTS: The rate of bacteriuria after FC was reduced from 9% in the placebo group to 5% and 3% in patients receiving trimethoprim and ciprofloxacin prophylaxis, respectively. When rates of bacteriuria before FC were considered the odds of developing bacteriuria after FC relative to baseline were 5, 2 and 0.5 for placebo, trimethoprim and ciprofloxacin, respectively. CONCLUSION: This large trial shows clearly that one dose of oral ciprofloxacin significantly reduces bacteriuria after FC.