OBJECTIVEErectile dysfunction (ED) is now recognized as a comorbid condition, especially in men with cardiovascular disease or diabetes mellitus. This randomized controlled trial was to examine the effect of long-term small-dose tadalafil in the treatment of ED.

METHODSA total of 98 men older than 18 years with at least a 6-month ED history were enlisted and divided into two groups to receive once-daily treatment with tadalafil at 5 mg (n = 60) and 20 mg (n = 38), respectively, for 12 months. The effects of medication were analyzed and compared using IIEF, Global Assessment Questionnaire (GAQ) and Sexual Encounter Profile (SEP), and so were the safety and tolerance of the two doses.

RESULTSThere were no statistically significant differences in the therapeutical results between the 5 mg and 20 mg groups (P < 0.05). The IIEF-5 score was raised by 8.1 points in the former and 7.9 points in the latter; the YES answers to SEP2 in the two groups were 51.3% and 49.2% before the treatment and 82.6% and 84.9% after it. No serious adverse events were observed, except some common ones, such as rubeosis (11.9% vs 8.7%) and headache (5.3% vs 4.9%) in the 5 mg and 20 mg groups.

CONCLUSIONOral tadalafil at 5 mg once daily is efficacious with good tolerance in the treatment of ED, and it can be an alternative to on-demand medication for some men to eliminate the inconvenience of planned intercourse within a limited timeframe.