Benign prostatic hyperplasia (BPH) is a nonmalignant enlargement of the prostate which can result in bothersome lower urinary tract symptoms. The treatment goal for men with BPH is to relieve these bothersome symptoms.
This systematic review assessed the effects of tamsulosin in the treatment of lower urinary tract symptoms (LUTS) compatible with BPH.
Trials were searched in computerized general and specialized databases (MEDLINE, EMBASE, Cochrane Library), by checking bibliographies, and by contacting manufacturers and researchers.
Trials were eligible if they (1) randomized men with BPH to receive tamsulosin in comparison with placebo, other BPH medications or surgical interventions and (2) included clinical outcomes such as urologic symptom scales, symptoms, or urodynamic measurements, and (3) had a treatment duration of 30 days or longer. Eligibility was assessed by at least two independent observers.
Information on patients, interventions, and outcomes were extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of tamsulosin with placebo, medical or surgical interventions was the change in urologic symptom scale scores. Secondary outcomes included changes in urinary flow measures (peak urine flow rate). The main outcome measure for adverse effects was the number of men reporting adverse effects.
Fourteen studies involving 4,122 subjects met inclusion criteria. Study duration ranged from 4-26 weeks, and no placebo-controlled study lasted longer than 13 weeks. The mean age of subjects was 64 years. Baseline symptom scores and urine flow rates demonstrated that men had moderate LUTS. Tamsulosin improved symptoms and peak urine flow relative to placebo. The weighted mean differences (WMD) for mean change from baseline for the Boyarsky symptom score for 0.4 mg and 0.8 mg doses of tamsulosin relative to placebo were -1.1 points (95% CI = -1.49, -0.72; 12% improvement) and -1.6 points (95% CI = -2.3, -1.0; 16% improvement), respectively. The WMD for mean change from baseline in peak urine flow were 1.1 mL/sec (95% CI = 0.59, 1.51) and 1.1 mL/sec (95% CI= 0.65, 1.48) for 0.4 mg and 0.8 mg, respectively. Tamsulosin (0.2 mg-0.4 mg) was as effective as other alpha antagonists and the phytotherapeutic agent Permixon in improving symptoms and flow rates though the doses of all alpha-antagonists studied may not have been optimal. Discontinuations from treatment for any reason and discontinuations "due to adverse events" were similar in the low dose tamsulosin (0.2 mg) and placebo groups but increased to 16% in trials utilizing a 0.8 mg dose of tamsulosin. Low dose tamsulosin was generally well tolerated although not all the trials reported specific adverse events. The most frequently reported adverse events that were significantly greater than placebo included dizziness, rhinitis and abnormal ejaculation. Adverse effects increased markedly as tamsulosin dosing increased, and were reported in 75% of men receiving the 0.8 mg dose. Men receiving a 0.2 mg dose tamsulosin were less likely to discontinue treatment compared to men receiving terazosin.
Tamsulosin provided a small to moderate improvement in urinary symptoms and flow compared to men receiving placebo in men with BPH. Effectiveness was similar to other alpha antagonists and increased only slightly with higher doses. Long term effectiveness and ability to reduce complications due to BPH progression could not be determined. Adverse effects were generally mild but their frequency, including withdrawals, increased substantially with the higher doses that are generally available for treatment.