Objective: To determine whether patients with erectile dysfunction (ED) and treated with tadalafil use the 36-h duration of effect of the drug, and to discern if the timing of intercourse attempts is influenced by patient age, baseline severity of ED, or previous experience with sildenafil citrate.
Patients and methods: In 11 multicentre, double-blind, placebo-controlled studies, 2102 patients with ED were randomized to a maximum of one dose per day of tadalafil 10 or 20 mg (1464 men), or placebo (638 men) with no time restrictions before attempting sexual activity after the dose. A post hoc analysis was used to determine the proportion of men with ED who attempted sexual intercourse during various intervals (>0 to < or = 1, >1 to < or = 4, and >4 to < or = 36, including >12 to < or = 36 h) after dosing with tadalafil or placebo over a 12-week period. Patients were stratified by age, baseline severity of ED, and previous history of sildenafil use.
Results: Of patients in different age groups and various ED severity, > or = 79% and > or = 53% chose to attempt sexual intercourse at least once during the 12-week treatment period at 4-36 and 12-36 h, respectively, after taking tadalafil. Regardless of previous experience with sildenafil, about a third of patients using tadalafil attempted intercourse a mean of at least once per week at 4-36 h after the dose over 12 weeks. Furthermore, 58% of patients attempted intercourse at least once during two intervals (>1 to < or = 4 h and >12 to < or = 36 h) after separate doses of tadalafil.
Conclusion: Regardless of age, ED severity, or previous experience with sildenafil, most patients attempted sexual intercourse at least once at 12-36 h after one dose of tadalafil over a 12-week treatment period. Furthermore, by engaging in sexual intercourse at both earlier and later intervals after separate doses, most patients on treatment did not adhere to a fixed schedule of intimacy and thus took advantage of the 36-h duration.