Material and Method: This prospective, Cohort study was conducted for eight weeks. Two hundred ten male patients, older than 20 years of age with ED were enrolled to receive generic product of sildenafil 100 mg taken as needed. Efficacy is evaluated through the International Index of Erectile Function (IIEF) scores for the five separate response domains, erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction domain.

Results: After sildenafil administration, erectile function domain scores were significantly increased from baseline, 5.02 (p<0.001) and 7.19 (p<0.001) in one month and two months, respectively. Intercourse satisfaction domain scores and overall satisfaction domain scores were significantly increased from baseline, 3.17 (p<0.001) and 1.74 (p<0.001) in two months, respectively. Most treatment emergent adverse events were mild or moderate. The most frequent treatment-emergent adverse events were flushing (13.2%), nasal congestion (9.8%), abnormal vision (4.9%), headache (4.4%), dizziness (2.9%), and dyspepsia (0.5%)

Conclusion: Elonza®, a generic product of sildenafil, was an effective and well-tolerated treatment for ED in Thai men.

Keywords: Sildenafil, Erectile dysfunction, International index of erectile function