Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial

Objectives. The National Institutes of Health (NIH) category III chronic pr ostatitis syndromes (nonbacterial chronic prostatitis and prostatodynia) ar e common disorders with few effective therapies. Bioflavonoids have recentl y been shown in an open-label study to improve the symptoms of these disord ers in a significant proportion of men. The aim of this study was to confir m these findings in a prospective randomized, double-blind, placebo-control led trial. Methods. Thirty men with category IIIa and IIIb chronic pelvic pain syndrom e were randomized in a double-blind fashion to receive either placebo or th e bioflavonoid quercetin 500 mg twice daily for I month. The NIH chronic pr ostatitis symptom score was used to grade symptoms and the quality-of-life impact at the start and conclusion of the study. In a follow-up unblind, op en-label study, 17 additional men received month of a supplement containing quercetin, as well as bromelain and papain (Prosta-Q), which enhance biofl avonoid absorption. Results, Two patients in the placebo group refused to complete the study be cause of worsening symptoms, leaving 13 placebo and 15 bioflavonoid patient s for evaluation in the blind study. Both the quercetin and placebo groups were similar in age, symptom duration, and initial symptom score. Patients taking placebo had a mean improvement in NIH symptom score from 20.2 to 18. 8 (not significant), while those taking the bioflavonoid had a mean improve ment from 21.0 to 13.1 (P = 0.003). Twenty percent of patients taking place bo and 67% of patients taking the bioflavonoid had an improvement of sympto ms of at least 25%. In the 17 patients who received Prosta-Q in the open-la bel study, 82% had at least a 25% improvement in symptom score. Conclusions, Therapy with the bioflavonoid quercetin is well tolerated and provides significant symptomatic improvement in most men with chronic pelvi c pain syndrome. (C) 1999, Elsevier Science Inc.