Taking tadalafil once a day may benefit men who have not had much success with as-needed erectile dysfunction medications, American scientists report.
Their research involved 623 sexually-active men (mean age 57.6) who had had erectile dysfunction (ED) for at least three months. All of the men had been treated with phosphodiesterase type 5 (PDE5) inhibitors (sildenafil citrate, vardenafil, or tadalafil), taking the maximum dose allowed on an as-needed basis. While the men had seen some positive results from this previous treatment, their erections had not returned to normal.
The researchers wanted to know whether taking tadalafil once daily – instead of as-needed – would make a difference for these men.
To assess their erections, the researchers used the International Index of Erectile Function (IIEF). An IIEF score of 26 or below indicated ED. To be included, participants were required to have an IIEF score of 17 or higher, but below 26.
The research was conducted as two identical randomized, double-blind, parallel, placebo-controlled studies.
The trial began with a 4-week run-in period, during which the men were given 8 doses of their usual as-needed ED medication and asked to try intercourse at least four times. The next phase involved 4 weeks without medication.
Then, the men were randomly assigned to one of three groups. One group (207 men) took 2.5 to 5 mg of tadalafil once daily. A second group (207 men) took daily 5 mg doses of tadalafil. The third group (209 men) took a placebo. Treatment lasted for 12 weeks.
When compared to the placebo group, the men who took tadalafil saw a significant improvement in their erectile function. At the end of the study, 12.1% of the men in the placebo group had IIEF scores of 26 or higher. However, 38.7% of the men taking 2.5 to 5 mg of tadalafil and 39.6% of those taking 5 mg of tadalafil had scores in this range.
The men who took tadalafil also had higher rates of intercourse and overall sexual satisfaction, as assessed by the IIEF, when compared to the men who took the placebo. Their sexual confidence also improved.
“This suggests that tadalafil once daily may help improve psychosocial aspects of sexual functioning that could impact a man’s mental well-being,” the authors wrote.
Tadalafil taken once daily was generally well-tolerated. The most commonly-reported side effect was headache, which affected less than 5% of the participants.
“Treatment with tadalafil once daily may be a viable option for men with ED that could help restore normal erectile function,” the researchers concluded.
The research was published online in July in the Journal of Sexual Medicine.
The Journal of Sexual Medicine
Kim, Edward D., et al.
“A Return to Normal Erectile Function with Tadalafil Once Daily after an Incomplete Response to As-Needed PDE5 Inhibitor Therapy”
(Full-text. First published online: July 10, 2013)
Renal and Urology News
“Daily Tadalafil May Aid Return to Normal Erectile Function”
(August 27, 2013)