Aim: Vardenafil is a highly selective phosphodiesterase type-5 inhibitor for the treatment of erectile dysfunction (ED). Efficacy of vardenafil has been demonstrated in various ED populations, but that in Japanese patients with spinal cord injury (SCI) has not been assessed.
Methods: This was an open-label, multicenter, flexible dose, 12-week study in patients with ED due to SCI. Following a 4-week observation period, patients received vardenafil 10 mg for 4 weeks, and based on efficacy, tolerability and patient preference, doses for the remaining 8 weeks were decided by investigators. The primary efficacy parameter was erectile function domain score of the International Index of Erectile Function.
Results: Ten patients took 10 mg all through the study, while 22 patients took 20 mg after completing 4 weeks' treatment with 10 mg. The erectile function domain score increased from 12.2 at baseline to 25.0 at Last Observation Carried Forward (LOCF) in the former group and from 10.3 to 22.5 in the latter group, respectively. Importantly, there was a 5.0 point increase in erectile function domain score after up-titration in the latter group. Drug-related adverse events were observed in 22% of patients including hot flushes (9%) and headache (6%), but these were transient and mild in intensity. Serious adverse events and adverse events leading to discontinuation of the study drug were not reported.
Conclusions: Vardenafil 10 and 20 mg was well tolerated and improved erectile function in patients with SCI. Of interest, erectile function was further improved by 20 mg in patients who were not sufficiently treated with 10 mg.