Introduction. With once-daily administration of tadalafil, dosing and sexual activity would no longer need to be temporally linked for patients with erectile dysfunction (ED).
Aim. To evaluate long-term safety and efficacy of tadalafil 5 mg dosed once daily for the treatment of ED.
Methods. Patients ≥18 years of age with ED of any functional severity or etiology received tadalafil 5 mg once daily for 1 (N = 234) or 2 (N = 238) years during the open-label extensions of two previously reported studies. Patients who completed the 1-year open-label extension concluded with a 4-week ED treatment-free period. Baseline was defined as prior to receiving any study drug.
Main Outcome Measures. Safety measures included adverse events, electrocardiograms, and clinical laboratory measures. Efficacy measures included the International Index of Erectile Function (IIEF)-Erectile Function (-EF), -Intercourse Satisfaction (-IS), and -Overall Satisfaction (-OS) domain scores, and the Global Assessment Questions (GAQ1: improved erections; GAQ2: improved ability to engage in sexual activity).
Results. Overall, 208/234 (88.9%) and 139/238 (58.4%) patients completed the 1- and 2-year open-label extensions, respectively. No study drug-related serious adverse events were observed. Treatment-emergent adverse events observed in ≥5% of the patients during the first year of either open-label extension were dyspepsia, headache, back pain, and influenza. No clinically meaningful abnormalities associated with tadalafil were observed for electrocardiograms or clinical laboratory measures. Mean IIEF domain scores improved from baseline to the conclusions of the 1- and 2-year open-label extensions, respectively: -EF, +10.4 and +10.8; -IS, +4.0 and +3.7; and -OS, +3.0 and +3.2. At the conclusion of the 2-year open-label extension, 95.7% and 92.1% of the patients reported positive responses to GAQ1 and GAQ2, respectively.
Conclusions. In these long-term, open-label, once-daily dosing studies, tadalafil 5 mg was well tolerated and effective, making it a viable alternative to the current on-demand dosing of tadalafil for men with ED. Porst H, Rajfer J, Casabé A, Feldman R, Ralph D, Vieiralves LF, Esler A, Wolka AM, and Klise SR. Long-term safety and efficacy of tadalafil 5 mg dosed once daily in men with erectile dysfunction. J Sex Med 2008;5:2160–2169.