Comparative efficacy and safety profile of 4 vs 8 mg of silodosin once daily usage in patients with benign prostatic hyperplasia–related lower urinary tract symptoms divided into subgroups according to International Prostate Symptom Score severity

BACKGROUND: The purpose of this study was to compare once daily (QD) usage of 4 and 8 mg of silodosin in patients divided as those with moderate and with severe lower urinary tract symptoms (LUTSs) according to International Prostate Symptom Score (IPSS) categories in terms of effectiveness and adverse events. METHODS: A total of 234 patients aged ≥ 40 years were evaluated prospectively. All participants were divided firstly into two groups according to their IPSS severity as moderate and severe. They were further allocated to receive 4 mg of silodosin and 8 mg of silodosin QD. Demographic features and laboratory tests were recorded. The patients were questioned with International Index of Erectile Function-5 and IPSS along with quality of life index. Uroflowmetric measurements were applied to the patients. All tests and measurements were repeated at the 3rd month, and changes from pretreatment to posttreatment were analyzed by SPSS 21.0 Program. The statistical significance level was set at p < 0.05. RESULTS: Both treatments provided benefit in patients with both moderate and severe LUTSs. While results did not differ among 4 mg and 8 mg of silodosin in patients with moderate LUTSs, 8 mg of silodosin was significantly better than 4mg in those with severe LUTSs in terms of improvement of the total IPSS, IPSS voiding subtotal score, and quality of life score (p = 0.015, 0.030, <0.001, respectively). Both treatments did not affect erectile functions. Adverse events were seen more frequently in patients receiving 8 mg of silodosin than those treated with 4 mg of silodosin (p = 0.024). CONCLUSION: Our study revealed that 4 mg of silodosin QD was as effective as 8 mg of silodosin QD in patients with moderate LUTSs but not with severe LUTSs. It can be inferred from this study that prescription of 4 and 8 mg of silodosin may be chosen to treat the patients with moderate and severe LUTSs due to benign prostatic heperplasia, respectively.