Johnson MI et al. (2007) Oral ciprofloxacin or trimethoprim reduces bacteriuria after flexible cystoscopy. BJU Int 100: 826–829

Diagnostic flexible cystoscopy is a routine procedure performed in outpatient clinics and hospitals under local anesthetic: at least 220,000 took place in 2004–2005. Significant bacteriuria occurs in ∼8% of patients undergoing routine flexible cystoscopy, with considerable morbidity and costs for health services. The use of prophylactic antibiotics is an option, but this raises concerns about the development of antibiotic resistance.

It has been suggested that a single prophylactic dose of an oral antibiotic might reduce post-cystoscopy bacteriuria without significantly increasing the risk of resistance. This would represent a definite benefit to both patients and health services. Unfortunately, studies that have investigated the effect of a single prophylactic dose of antibiotic given at the time of flexicble cystoscopy have been too small to produce definitive results.

To resolve this, Johnson et al. carried out a large, prospective, double-blind, randomized controlled trial that involved 2,481 patients who were given either a placebo, one 200 mg oral dose of trimethoprim or one 500 mg oral dose of ciprofloxacin, 1 hour before undergoing flexible cystoscopy. These results were definitive: 9% of the placebo group developed bacteriuria after cystoscopy, but only 5% and 3% of the trimethoprim and ciprofloxacin groups, respectively (P <0.001), suffered infections. On the basis of their trial results, the authors believe that giving a single prophylactic oral dose of ciprofloxacin to patients undergoing flexible cystoscopy under local anesthetic would reduce both healthcare costs and the risks of resistance.