ABSTRACT
<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>After 4 weeks of tadalafil treatment, 11 (73.3%) of the cases were remarkably improved, with significant difference in IIEF-5 scores before and after treatment (P < 0.05). Transient adverse reactions were observed in the other 4 cases, including mild headache in 2, slight backache in 1, and facial flush in 1.</p><p><b>CONCLUSION</b>Oral tadalafil on alternate days is safe and effective in the treatment of ED that fails to respond to on-demand medication of sildenafil.</p>