For men who don’t respond to on-demand tadalafil (Cialis), a low daily dose may do the trick, researchers said here.
About 40% of men who took up to 5 mg of tadalafil every day were able to achieve normal erectile function even if they’d failed as-needed treatment, Edward Kim, MD, of the University of Tennessee Medical Center in Knoxville, and colleagues reported at the World Meeting on Sexual Medicine.
Although on-demand treatment with phosphodiesterase 5 (PDE5) inhibitors is highly effective for most men, Kim said, some don’t achieve normal erectile function, even with maximum doses.
To assess whether men for whom on-demand treatment didn’t work would do any better on daily tadalafil, the researchers conducted two double-blind, randomized, controlled trials in 623 men who had a mean age of 58.
All of the men had no response to as-needed treatment over the course of a month. After an additional one-month washout period, they were randomized to one of three groups: tadalafil 2.5 mg titrated to 5 mg, 5 mg, or placebo every day for 12 weeks.
Erectile function, as measured on the International Index of Erectile Function (IIEF-EF) significantly improved over the study period for men who had taken either dose of tadalafil compared with placebo — a score of at least 26 was achieved by 39% of those on the 2.5 mg titrated to 5, 40% of those on 5 mg daily, and 12% of those on placebo (P<0.001).
On average, men treated with either dose of daily tadalafil had an 8-point increase in IIEF-EF domain scores by the end of the trial compared with only a 2-point increase for men on placebo (P<0.001).
They also had significantly greater improvements on the Sexual Encounter Profile (SEP-3) questionnaire with either dose of tadalafil compared with placebo (38% and 40% versus 12%, P<0.001).
Kim added that both daily doses of the drug were well tolerated, and that any adverse events were consistent with those seen in previous trials.
He cautioned, however, that the study was limited because it didn’t include an arm for a daily tadalafil dose of only 2.5 mg, and because it involved only a 4-week as-needed dosing period.
Still, he concluded that taking tadalafil once a day “may be a viable option for men with erectile dysfunction that could help restore normal erectile function.”