The Chronic Prostatitis Collaborative Research Network (CPCRN), which consists of six clinical centers and one data coordinating center, was established to study all aspects of chronic prostatitis with the hope of improving diagnosis and treatment. Because the cause of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is unknown, affected men receive many empirical therapies. The two most common treatments prescribed by physicians are antimicrobial agents (including quinolones such as ciprofloxacin) and α-adrenergic receptor antagonists (such as tamsulosin), although there is little objective evidence to support their use. Based on these common clinical practices, the CPCRN conducted a randomized, two-by-two factorial design double-bind, clinical trial (CPCRN RCT#1) to evaluate whether ciprofloxacin or tamsulosin reduces symptoms of long-standing CP/CPPS of at least moderate severity.

Men with CP/CPPS from 11 clinical centers were enrolled and randomly assigned in equal proportions to receive placebo; ciprofloxacin alone, 500 mg twice daily; tamsulosin alone, 0.4 mg once daily; or a combination of both drugs. Patients were treated for 6 weeks, at which time the primary endpoint was assessed. Symptoms at 9 and 12 weeks after randomization (3 and 6 weeks after completion of treatment) were also assessed to evaluate longer-term treatment response. The primary outcome measure was the change in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score from baseline to 6 weeks. Secondary outcome meaures included changes in the pain, voiding, and quality-of-life subscales of the NIH-CPSI; physical and mental summary scores on the Medical Outcomes Study 12-Item Short-Form Health Survey; and a 7-point patient-reported global response assessment. All adverse events were monitored and analyzed.

The study found that neither ciprofloxacin nor tamsulosin significantly reduced the NIH-CPSI total score over 6 weeks compared with placebo. Moreover, neither treatment showed a significant benefit among a wide range of secondary outcomes related to symptoms and quality of life. Findings do not support the use of these agents as empirical therapy for men with long-standing CP/CPPS and at least moderate symptoms.

This CPCRN study was designed to evaluate whether ciprofloxacin or tamsulosin reduces symptoms of long-standing CP/CPPS of at least moderate severity. The primary purpose of the trial was to test the most common prescription treatments given to men with CP/CPPS.

The primary outcome measure was the change in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score from baseline to 6 weeks. Secondary outcome measures included changes in the pain, voiding, and quality-of-life subscales of the NIH-CPSI; physical and mental summary scores on the Medical Outcomes Study 12-Item Short-Form Health Survey; and a 7-point patient-reported global response assessment. All adverse events were monitored and analyzed.

Participants with CP/CPPS were referred from their providers. The primary criterion for eligibility was pain or discomfort in the pelvic region for at least 3 months in the previous 6 months. Exclusion criteria are documented in the study protocol.

The study found that neither ciprofloxacin nor tamsulosin significantly reduced the NIH-CPSI total score over 6 weeks compared with placebo. Moreover, neither treatment showed a significant benefit among a wide range of secondary outcomes related to symptoms and quality of life. Analyses of outcomes at 12 weeks demonstrated that additional changes after the end of treatment at 6 weeks were minimal. Findings do not support the use of these agents as therapy for men with long-standing CP/CPPS and at least moderate symptoms.