Objective: To compare the safety and efficacy of levofloxacin 750 mg QD for 2 weeks or levofloxacin 750 mg QD for 3 weeks to levofloxacin 500 mg QD for 4 weeks in treating chronic bacterial prostatitis (CBP).
Research design and methods: This was a randomized, multicenter, double-blind, noninferiority study. The primary efficacy end point was investigator assessment of clinical success in the modified intent-to-treat (mITT) population at post-therapy. National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) scores were utilized to evaluate subject-reported responses post-therapy.
Results: A total of 241 subjects were enrolled. At post-therapy (test of cure [TOC]), clinical success rates for levofloxacin-treated subjects (750 mg QD for 3 weeks [64.9%, 48/74]) were noninferior to 500 mg QD for 4 weeks (69.3%, 52/75: 95% CI, -19.5%, 10.6%). Success rates with levofloxacin 750 mg QD for 2 weeks (63.0%, 46/73) were not noninferior to therapy with levofloxacin 500 mg QD for 4 weeks (95% CI, -21.5%, 8.9%) at TOC. At 3 and 6 months post-therapy, clinical success rates were clinically higher for the 500-mg, 4-week treatment group, and statistical analysis demonstrated both groups were not noninferior to standard therapy with levofloxacin 500 mg (95% CI, -32.5%, -0.6% for both 750-mg groups at 6 months). NIH-CPSI scores showed similar trends. Overall, adverse event (AE) rates were similar for the three treatment groups; however, discontinuation of therapy due to AEs was higher with the 750-mg dose (p = 0.02, and p = 0.13 for 750 mg, 2 weeks and 750 mg, 3 weeks versus 500 mg for 4 weeks, respectively). The main limitation of this study was that no bacterial cultures were required.
Conclusions: Higher doses for shorter durations were determined to be no worse than standard therapy with levofloxacin 500 mg for a longer duration at the TOC visit. However, at the 6-month follow-up visit, the levofloxacin 750-mg dose administered for either 2 weeks or 3 weeks was inferior to the standard therapy, suggesting that a longer duration of treatment may help extend the relapse-free interval in patients with CBP.
Clinical trial registration: clinicaltrials.gov, nct00402688.
Trial registration: ClinicalTrials.gov NCT00402688.