Objective: [corrected] To compare the efficacy and safety of tadalafil 20 mg administered 3 times/week (SCH) vs. on demand (OD) in a cohort of Spanish men with erectile dysfunction (ED), since Tadalafil period of responsiveness lasts up to 36 hours post-dosing.
Material and methods: The 418 Spanish patients participating in the European multicenter, crossover, open-label SURE clinical trial (comprising 4262 men) were randomly assigned to one of the treatment sequences: tadalafil 20 mg SCH for 5-6 weeks followed by tadalafil 20 mg OD for 5-6 weeks, or the inverse sequence. At completion, patients were asked to select the regimen they preferred to receive in an extension phase.
Results: In both regimens, tadalafil led to a similar improvement in erectile function compared to baseline. However, the SCH regimen showed statistically significant higher scores for several IIEF questions (i.e. sexual desire domain). Normal erectile function (IIEF EF domain score > or = 26) was achieved by 69.3% of patients on SCH and 64.3 % on OD, with a sexual intercourse success rate (SEP3) of 75.6% and 72.2% respectively (p<0.05). Nevertheless, more patients preferred to receive tadalafil OD for the extension phase (55.9% vs 44.1%, p<0.05). Tadalafil was well tolerated in both regimens. The most common TEAEs (> or = 5%) were headache, dyspepsia and back pain. There were no clinically significant differences in the incidence of TEAEs between regimens.
Conclusions: Tadalafil 20 mg is efficacious and well tolerated for the treatment of ED, regardless the regimen of administration (OD or SCH). Patients can choose the pattern of administration that fits better with their expectations.