Single-dose Versus 3-day Antimicrobial Prophylaxis in Transurethral Resection or Photoselective Vaporization of the Prostate: A Multicenter, Randomized, Placebo Controlled Trial (CITrUS Trial).

Background and objective: Guidelines recommend single-dose antimicrobial prophylaxis (AMP) for transurethral resection (TURP) and photoselective vaporization (PVP) of the prostate. As guideline adherence is low and 3-d AMP is given frequently, we aimed to assess the noninferiority of a single dose compared with 3-d AMP by comparing the incidence of urinary tract infections (UTIs) within 30 d.

Methods: A double-blind, multicenter, randomized, noninferiority trial was conducted comparing single-dose with 3-d AMP in patients assigned to TURP and PVP, assuming a 9% event rate for a clinical diagnosis of a UTI with a 4.4% noninferiority margin.

Key findings and limitations: From anticipated 1574 patients, 728 were recruited and 621 randomized patients were analyzed fully. The study was preliminary stopped due to delayed recruitment and was analyzed exploratively. Following single-dose AMP, 11.0% of patients (95% confidence interval [CI] 7.9%, 15.0%; 33/300) had a clinical diagnosis of UTIs, compared with 8.5% (95% CI 5.8%, 12.1%; 26/307) receiving 3-d AMP (between-group difference 2.5% [95% CI -2.2%, 7.5%]). The rates of UTIs supported by bacteriuria were lower without any difference between groups (single-dose AMP: 3.3% [95% CI 1.8%, 6.0%]; 3-d AMP: 3.3% [95% CI 1.8%, 5.9%]; between-group difference 0.08% [95% CI -2.97%, 3.16%]). Adverse events were rare.

Conclusions and clinical implications: In this randomized trial of transurethral prostate surgery patients, 11.0% of those on single-dose AMP and 8.5% on 3-d AMP were diagnosed with UTIs. The smaller than planned sample size precludes a definite interpretation favoring either group. Diagnoses of UTIs based on symptoms and bacteriuria reduced the overall rates and group differences.