[Oral tadalafil on alternate days for erectile dysfunction that fails to respond to on-demand sildenafil: a report of 15 cases].

Objective: To sum up the experience in administering oral tadalafil on alternate days for the treatment of erectile dysfunction (ED) that fails to respond to on-demand medication.

Methods: We retrospectively analyzed the clinical data of 15 cases of ED treated with oral tadalafil on alternate days from September 2010 to March 2012. All the patients had failed to respond to on-demand medication of sildenafil previously.