According to a summary of data from these trials, the benefits of therapy defined as either the 2-Methoxyestradiol mw treatment effect (Figure 1) or the percentage of responders (Figure 2) have varied widely. To our knowledge, comparative studies of α1-blockers in patients with CP/CPPS
have not been conducted. Figure 1 Treatment effect associated with the use of α-blockers measured Inhibitors,research,lifescience,medical according to the National Institutes of Health Chronic Prostatitis Symptom Index during randomized, placebo-controlled clinical studies of patients with chronic prostatitis/chronic … Figure 2 Percentage of responders during randomized clinical trials of α-blockers in patients with chronic prostatitis/chronic pelvic pain syndrome. aP = .03 for terazosin vs placebo at 38 weeks.22 bNot all treatment arms are shown; a total of 196 patients … Many earlier studies evaluated the use of second-generation α-adrenergic blockers (ie, doxazosin, terazosin) nonselective for a specific receptor subtype, whereas
more recent studies have evaluated the third-generation uroselective Inhibitors,research,lifescience,medical agents tamsulosin and silodosin in patients with CP/CPPS.26,27 The third-generation agents are reported to have a higher affinity for the α1A-receptor, which is Inhibitors,research,lifescience,medical prevalent in human prostate tissues.13,33 Selectivity for the receptors in the prostate results in fewer adverse events mediated by α1B-receptor stimulation in the vasculature. For example, competitive binding experiments have found that the selectivity of silodosin is more than 100 times greater for the α1A than the α1B subtype, and that of tamsulosin is almost 10-fold Inhibitors,research,lifescience,medical greater with a moderate affinity for the α1D-subtype receptor.14 In those who receive treatment with second-generation α-adrenergic antagonists, postural hypotension and other cardiovascular side effects may be reduced by initiating treatment at the lowest starting dose, administering treatment at bedtime, and closely monitoring
blood pressure in patients who are receiving concomitant treatment with Inhibitors,research,lifescience,medical antihypertensive agents. Tamsulosin At this time, three prospective, placebo-controlled trials have evaluated the effects of the third-generation α-adrenergic antagonist tamsulosin as measured by the NIH-CPSI in patients with CP/CPPS.23,26,30 The most recent trial by Chen and colleagues was the first to evaluate the longer-term effects of an α1-blocker in a prospective, randomized Thalidomide study.26 This placebo- controlled, prospective phase III study was conducted in 100 Chinese men with a ≥ 3-month history of pain or discomfort in the pelvic region who had not received prior treatment with α1-blockers.26 In this study, patients were randomized to treatment for 6 months with a low dose of tamsulosin (0.2 mg) or placebo to determine the effects of tamsulosin on symptom relief, as measured by change in NIH-CPSI during treatment and over a 2-year follow-up period.