Evaluation of silodosin in comparison to tamsulosin in benign prostatic hyperplasia: a randomized controlled trial.

OBJECTIVES: Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms in elderly men. Selective alfa1-adrenergic antagonists are now first-line drugs in the medical management of BPH. We conducted a single-blind, parallel group, randomized, controlled trial to compare the effectiveness and safety of the new alfa1-blocker silodosin versus the established drug tamsulosin in symptomatic BPH.

MATERIALS AND METHODS: Ambulatory male BPH patients, aged above 50 years, were recruited on the basis of International Prostate Symptom Score (IPSS). Subjects were randomized in 1:1 ratio to receive either tamsulosin 0.4 mg controlled release or silodosin 8 mg once daily after dinner for 12 weeks. Primary outcome measure was reduction in IPSS. Proportion of subjects who achieved IPSS <8, change in prostate size as assessed by ultrasonography and changes in peak urine flow rate and allied uroflowmetry parameters, were secondary effectiveness variables. Treatment emergent adverse events were recorded.

RESULTS: Data of 53 subjects - 26 on silodosin and 27 on tamsulosin were analyzed. Final IPSS at 12-week was significantly less than baseline for both groups. However, groups remained comparable in terms of IPSS at all visits. There was a significant impact on sexual function (assessed by IPSS sexual function score) in silodosin arm compared with tamsulosin. Prostate size and uroflowmetry parameters did not change. Both treatments were well-tolerated. Retrograde ejaculation was encountered only with silodosin and postural hypotension only with tamsulosin.

CONCLUSIONS: Silodosin is comparable to tamsulosin in the treatment of BPH in Indian men. However, retrograde ejaculation may be troublesome for sexually active patients.