A randomised, double-blind, parallel, placebo-controlled study of the efficacy and safety of Tadalafil administered on-demand to men with erectile dysfunction in Korea

Purpose: Tadalafil is a phosphodiesterase type 5 inhibitor that is used for the treatment of erectile dysfunction (ED). Previous clinical trials have assessed its efficacy and safety in Western populations, but this drug has not been investigated in a large clinical trial involving Korean men with ED. Thus, the aim of this study was to assess the efficacy and safety of 20 mg tadalafil in comparison to placebo when it is taken on demand by Korean men suffering with ED over a study period of 12 weeks. Materials and Methods: Men more than 18 years of age with mild to severe ED of various etiologies were randomized to receive placebo or tadalafil 20 mg that was taken as needed (maximum once daily). Efficacy assessments included the International Index of Erectile Function (IIEF), the Sexual Encounter Profile (SEP) diary and Global Assessment Questions (GAQ). Results: Tadalafil significantly improved erectile function, as measured by the erectile function domain of the IIEF, compared to placebo (p < 0.001). At the endpoint, the patients receiving tadalafil 20mg reported a greater mean per-patient percentage of successful intercourse attempts (SEP3: 71% compared to 31% for placebo) and a greater proportion of improved erections (GAQ: 80% compared to 44%). The most common treatment emergent adverse events were headache (16.3%), flushing (5%) and eye pain (5%), and most of the adverse events were mild or moderate in severity. Conclusions: Tadalafil was an effective, well-tolerated therapy for Korean men suffering with ED of broad-spectrum severity and etiology.