Symptomatic and urodynamic responses in patients with reduced or no seminal emission during silodosin treatment for LUTS and BPH.

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.

Effects of the selective alpha 1a-adrenoceptor antagonist silodosin on ECGs of healthy men in a randomized, double-blind, placebo- and moxifloxacin-controlled study.

In order to determine the effects of therapeutic and supratherapeutic doses of silodosin on QT interval, healthy men (N = 186; aged 18-45 years) were randomized to receive silodosin (8 or 24 mg) or placebo for 5 days or moxifloxacin 400 mg (positive control, known to prolong QT) once on day 5. At baseline and on day 5, five ECGs were recorded 0.25 h before dosing and 1, 1.5, 2, 3, 4, 6, 8, 10, and 23.5 h after dosing. Adjusted mean differences (analysis of covariance) between silodosin and placebo in the change in individual heart rate-corrected QTc (QTcI) from baseline to day 5 were <5 ms at all times (all 90% confidence interval (CI) upper limits <10 ms). The QTcI difference for moxifloxacin compared with placebo often exceeded 5 ms, establishing assay sensitivity. For silodosin, no statistically or clinically significant correlation was seen between plasma concentration and QTcI, and no clinically important effects on heart rate, PR segment, QRS complex, or morphologic ECG data were observed.