Is antibiotic prophylaxis required for flexible cystoscopy? A truncated randomized double-blind controlled trial.

PURPOSE

To examine the incidence of urinary tract infection (UTI) after flexible cystoscopy (FC) and determine whether prophylactic norfloxacin reduces this incidence compared with placebo.

PATIENTS AND METHODS

A double-blind trial was performed, randomizing 234 patients to either 400 mg of norfloxacin or placebo prior to FC. All patients provided a midstream urine specimen (MSU) before the procedure, as well as at day 3 and day 7 after FC. In addition, a telephone questionnaire was performed to correlate the nature and severity of any symptoms associated with UTI.

RESULTS

Interim analysis was performed because of the low recruitment rate, and a significantly lower infection rate than expected meant that the trial was discontinued. There was one symptomatic UTI in the placebo group (0.82%) and one in the norfloxacin group (0.89%). The UTI in the placebo group was de novo, while the infection in the norfloxacin group was secondary to pre-FC bacteriuria. There was no difference in the infection rates in the two groups. The overall infection rate (de novo and secondary to existing bacteruria) after FC was 0.85%.

CONCLUSION

Infection after flexible cystoscopy is rare and not associated with significant morbidity. A much larger study would be required to determine whether antibiotic prophylaxis significantly reduces the rate of postprocedure UTI.