Data to be presented at the American Urological Association's (AUA) Annual Conference show that Rapaflo (silodosin) produces rapid and sustained improvements of both irritative and obstructive urinary symptoms associated with BPH, with statistically significant symptom relief within three to four days of starting treatment. Rapaflo is a new, uniquely selective alpha blocker for the treatment of the signs and symptoms of BPH, launched earlier this month by Watson Pharmaceuticals, a leader in generic and specialty branded pharmaceuticals.
A separate abstract, also presented at the conference, found that men taking Rapaflo who experienced a treatment related effect called retrograde ejaculation (orgasm with reduced semen) trended to greater improvement in symptom relief and peak flow. This observation suggests that Rapaflo relaxes smooth muscles of the lower urinary tract significantly enough to relieve symptoms as well as to induce this effect in some patients. Retrograde ejaculation does not pose a safety concern and is reversible upon discontinuation of treatment. In Rapaflo clinical trials, rates of discontinuation due to retrograde ejaculation were low.
"Our observation suggests that retrograde ejaculation is actually an indirect indicator of the relaxation of the smooth musculature that Rapaflo induces," said Dr Steve A Kaplan, tenured professor of urology at Weil Cornell Medical College, Cornell University, and an author of one of the AUA abstracts. "For the older BPH patient who experiences retrograde ejaculation, it may be a small trade off for the rapid and significant relief of urinary symptoms that treatment with Rapaflo offers."
BPH is the number one reason patients visit urologists and is characterized by urination problems, including decreased urine flow, more frequent urination and nocturia.
The first abstract was a post-hoc analysis of two randomized, placebo-controlled, double-blind clinical trials involving 923 men ages 50 or older with signs and symptoms of BPH, including a peak urine flow rate (Qmax) between four and 15 mL/sec (mean of 8.7 to 8.9) and International Prostate Symptom Score (IPSS) greater than or equal to 13 (mean of 21.3). Patients were randomized to either 8 mg Rapaflo once daily (n=466) or placebo (n=457) for 12 weeks. In this analysis, researchers assessed changes in IPSS subscales by evaluating seven questions related to irritative symptoms (frequency, urgency and nocturia) and obstructive symptoms (incomplete emptying, intermittency, weak stream and straining). Mean baseline scores for all seven measures were very similar between the two groups.
Rapaflo is an effective, uniquely selective alpha-1 adrenergic receptor antagonist. Rapaflo maximizes target organ activity by binding with high affinity to the alpha (1A) receptors concentrated in the prostate.