TUCSON, ARIZ. — Monotherapy with sildenafil provides relief for men with both erectile dysfunction and lower urinary tract symptoms, Dr. Jay Young and his associates reported in a poster at the annual meeting of the North American Primary Care Research Group.
The study randomized 369 men, aged 45 years and older, with lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) to sildenafil (Viagra) 50 mg or placebo nightly or 30–60 minutes before sexual activity. After 2 weeks, the sildenafil dose was titrated to 100 mg with the option of returning to 50 mg if 100 mg was not tolerated.
Overall, 189 patients were treated with sildenafil and 180 patients took placebo. The cause of ED was organic in the majority of patients, with an average duration of about 5 years in both groups.
The intent-to-treat analysis included 366 men. Those receiving sildenafil had significantly greater mean improvement in erectile function domain scores on the International Index of Erectile Function, compared with placebo-treated patients (9.2 vs. 1.9), and in their International Prostate Symptom Scores (IPSS) (−6.3 vs. −1.9), Dr. Young reported.
He has been an investigator for, owns stock in, and is on the speaker's bureau of Pfizer Inc., which sponsored the study.
Secondary end points were also significantly improved in sildenafil- vs. placebo-treated men, including irritative and obstructive symptoms, the IPSS quality-of-life question, and Benign Prostatic Hyperplasia Impact Index (BPHII) scores.
Maximum urinary flow rate (Qmax) increased slightly for both groups but was not significantly different between groups.
“The improvement in IPSS and BPHII score with no concomitant improvement in Qmax suggests that a new pathophysiology paradigm may be needed to explain the etiology of LUTS,” said Dr. Young, director of clinical research at South Orange County Medical Research Center in Laguna Woods, Calif.
A previous study, presented at the 2006 annual meeting of the European Association of Urology, reported that the combination of sildenafil 25 mg/day and the α1-blocker alfuzosin (Uroxatral) 10 mg/day was more effective than either agent was alone in men with previously untreated LUTS and ED.
It is possible that further improvement in LUTS would have been observed if alfuzosin had been added to the sildenafil in the current trial; however, that was not done, said Carl Clay, Ph.D., senior medical writer with Complete Healthcare Communications, which fielded questions on the study for Dr. Young.
Nine sildenafil patients dropped out of the current study because of adverse events, compared with two in the placebo group. The most common events were headache, dyspepsia, and respiratory tract infection.