Pregabalin for the treatment of men with chronic prostatitis/chronic pelvic pain syndrome: a randomized controlled trial

Abstract

Background: Evidence suggests that the urogenital pain of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) may be neuropathic.

Methods: This randomized, double-blind, placebo-controlled trial was conducted across 10 tertiary care centers in North America to determine whether pregabalin, which has been proved effective in other chronic pain syndromes, is effective in reducing CP/CPPS symptoms. In 2006-2007, 324 men with pelvic pain for at least 3 of the previous 6 months were enrolled in this study. Men were randomly assigned to receive pregabalin or placebo in a 2:1 ratio and were treated for 6 weeks. Pregabalin dosage was increased from 150 to 600 mg/d during the first 4 weeks. The primary outcome was a 6-point decrease in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) total score. Multiple secondary outcomes were assessed.

Results: Of 218 men assigned to receive pregabalin, 103 (47.2%) reported at least a 6-point decrease in the NIH-CPSI total score at 6 weeks compared with 35.8% (38 of 106 men) assigned to receive placebo (P = .07, exact Mantel-Haenszel test, adjusting for clinical sites). Compared with the placebo group, men assigned to receive pregabalin experienced reductions in the NIH-CPSI total score and subscores (P < .05), a higher Global Response Assessment response rate (31.2% and 18.9%; P = .02), and improvement in total McGill Pain Questionnaire score (P = .01). Results for the other outcomes did not differ between groups.

Conclusion: Pregabalin therapy for 6 weeks was not superior to placebo use in the rate of a 6-point decrease (improvement) in the NIH-CPSI total score in men with CP/CPPS.

Trial registration: clinicaltrials.gov Identifier: NCT00371033.

Figure 1

Flow of participants through the study phases. Patients had more than 1 reason to decline to participate.

Figure 2

Box and whisker plot comparing Chronic Prostatitis Symptom Index (CPSI) score changes from baseline to week 6 in the pregabalin and placebo arms for each domain. The horizontal line in the middle of each box indicates the median, and the top and bottom borders of the box mark the 75th and 25th percentiles, respectively. The whiskers above and below the box mark the 90th and 10th percentiles, respectively. The points beyond the whiskers are outliers beyond the 90th or 10th percentiles.