Clinical Safety Profile of Sildenafil in Singaporean Men with Erectile Dysfunction: Pre-Marketing Experience (ASSESS-I Evaluation)

Safety and tolerability of sildenafil citrate was assessed in a population subset of 60 Singaporean men with erectile dysfunction taken from the Asian Sildenafil Efficacy and Safety Study (ASSESS-I), a double-blind, placebo-controlled, flexible-dose study. The men, from two centres, with ≥ 6 months’ history of erectile dysfunction, were randomized to two treatment arms for 12 weeks. One group (30 patients) received sildenafil (initial dose 50 mg taken 1 h before sexual activity for the first 2 weeks, increased to 100 mg or decreased to 25 mg, according to efficacy and/or tolerability). The remaining 30 patients received a matching placebo. Incidence and type of adverse effects were evaluated at 2, 4, 8 and 12 weeks. Nine patients (30.0%) on sildenafil (33.1% in the full ASSESS-I study) and one patient (3.3%) on placebo (22.8% in the full ASSESS-I study) experienced treatment-related adverse events, the most frequent being headache in the sildenafil group (reported by five patients [16.7%]; 11.0% in the full ASSESS-I study). Flushing, visual disturbance, dizziness, insomnia, myalgia and back pain each occurred in one patient in the sildenafil group (3.3%); in the placebo group, one patient (3.3%) had headache. Importantly, the incidence of cardiovascular and respiratory system adverse events were relatively less than in the full ASSESS-I population (cardiovascular 3.3% in the present study versus 10.2% in the full ASSESS-I population; respiratory 3.3% versus 5.5%). All adverse events were transient and mild, and did not lead to treatment withdrawal. There was no effect on sitting blood pressure, heart rate or standard laboratory parameters; more importantly, there was no incidence of myocardial infarction, stroke or priapism. These results should reassure Singaporean patients and their physicians of the safety of sildenafil for erectile dysfunction.

References

https://doi.org/10.1177/147323000203000206