Abstract
Data from phase 3 studies (NCT00224107, NCT00224120) of silodosin for treatment of BPH symptoms were analyzed to examine the relationship between treatment efficacy and occurrence of abnormal ejaculation. Men aged ≥50 years with International Prostate Symptom Scores (IPSS) ≥13 and peak urinary flow rates (Qmax) of 4-15 ml s(-1) received placebo or silodosin 8 mg once daily for 12 weeks. Silodosin-treated patients were stratified by absence or presence of 'retrograde ejaculation' (RE). Groups were compared using analysis of covariance (for change from baseline) and responder analyses. Of the 466 patients receiving silodosin, 131 (28%) reported RE and 335 (72%) did not; 4 of the 457 patients receiving placebo (0.9%) reported RE. Most RE events in silodosin-treated patients (110/134; 82%) were reported as 'orgasm with absence of seminal emission.' Silodosin-treated patients with (+) and without (-) RE showed significant improvement in IPSS, Qmax and quality of life versus placebo (P<0.02). RE+ patients versus RE- patients experienced numerically greater improvement, but differences were not statistically significant (P>0.05). For RE+ patients, the odds of achieving improvement of ≥3 points in IPSS and ≥3 ml s(-1) in Qmax by study end were 1.75 times those for RE- patients (P=0.0127). Absence of seminal emission may predict superior treatment efficacy of silodosin in individual patients.