PARIS — Phosphodieterase-5 inhibitors may have a role in the relief of lower urinary tract symptoms, according to two studies presented at the annual congress of the European Association of Urology.
Daily tadalafil (Cialis) therapy significantly improved symptom scores in men with benign prostatic hyperplasia in a placebo-controlled, phase II trial reported by Dr. Kevin T. McVary.
The 12-week, double-blind study enrolled 281 participants. Not unexpectedly, a sexually active subset with erectile dysfunction also experienced significantly improved erectile function with tadalafil.
In the second study, investigators combined sildenafil (Viagra) with alfuzosin (Uroxatral), an alpha1-blocker, for previously untreated lower urinary tract symptoms (LUTS) and erectile dysfunction. Dr. Steven A. Kaplan reported that the combination was more effective than either agent alone in the three-armed study of 62 men who had the two conditions.
Dr. McVary, a professor of surgery at Northwestern University, Chicago, described his results as “somewhat provocative” and the benefits as comparable to others reported on the use of alpha-blockers for LUTS. Patients on tadalafil improved in all end points except for the Qmax measure of urinary peak flow.
“If you give combinations of medications, you might be able to enhance both sexual function and voiding function,” said Dr. Kaplan, a professor of urology at Cornell University, New York.
Daily Tadalafil
Dr. McVary and his colleagues randomly assigned men with benign prostatic hyperplasia to tadalafil (n = 138) or placebo (n = 143). Both groups had an average age in the early 60s (range, 45–82 years).
At baseline, nearly two-thirds of the men had moderate LUTS, defined as International Prostate Symptom Score (IPSS) results below 20. The remainder had severe LUTS, with IPSS results of 20–35. A greater proportion of the tadalafil group had erectile dysfunction (72%), compared with the placebo group (59%).
After wash-out and placebo run-in periods, patients began taking either 5 mg of tadalafil or placebo at week 3. They continued at this daily dose for another 3 weeks, then moved to a 20-mg dose.
Average IPSS results declined by 2.8 points, compared with baseline, for the men on the 5-mg tadalafil dose.
Increasing the dose to 20 mg brought the decline to 3.8 points by the end of the 12-week trial. The placebo group's scores fell by 1.2 points at week 6 and 1.7 points at week 12.
Tadalafil also improved LUTS and International Index of Erectile Function (IIEF) scores for the subset (56%) who were sexually active and had erectile dysfunction, but the correlation was weak.
“There was a disconnect,” Dr. McVary said. “There were patients who had improvement in symptom scores for IPSS that did not directly correlate or correspond to changes in sexual function.”
He described tadalafil as well tolerated with no serious adverse events. The most frequent treatment-related side effects were increased erection, dyspepsia, back pain, and headache.
Lilly ICOS LLC funded the study.
Sildenafil Plus Alfuzosin
Dr. Kaplan and his colleagues randomized 62 consecutive men, with an average age of 63 years (range 50–76 years). For 12 weeks, 20 men took 10 mg daily of alfuzosin, an alpha1-blocker that has been shown to relieve LUTS with “minimal sexual and cardiovascular side effects.” Another 21 men took 25 mg of sildenafil each day. The other 21 men took both.
All three groups had significant improvements on the IPSS at 12 weeks. Scores fell from 17.8 to 14.6 with alfuzosin alone, from 16.9 to 14.9 with sildenafil alone, and from 17.3 to 13.5 with both.
Alfuzosin significantly improved frequency, nocturia, peak flow rate (Qmax), and postvoid residual urine equally well when used alone or in combination. Sildenafil alone did not have a significant effect.
All arms of the study showed improvement in erectile function, frequency of penetration, and frequency of maintained erections after penetration. Notably, IIEF scores went from 17.4 to 20.3 with alfuzosin alone, from 14.3 to 21.4 with sildenafil alone, and from 16.2 to 25.7 with both agents. These changes reached significance only in the sildenafil arms.
Seven patients dropped out because of dizziness, flushing, or dyspepsia.