Safety and efficacy of vardenafil in patients with erectile dysfunction: Result of a bridging study in Japan

Abstract

Aim : Vardenafil is a selective and highly potent phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), with improved selectivity for PDE5 and demonstrated efficacy for improving sexual function in men with ED. The current study investigated the safety and efficacy of this new PDE5 inhibitor in Japanese men with ED.Methods : This was a prospective, double blind, randomized clinical trial designed to evaluate the efficacy and safety of vardenafil. Following a 4-week treatment-free observation period, 283 eligible patients were randomized to 12 weeks treatment with vardenafil 5 mg, 10 mg, 20 mg, or placebo. Primary efficacy responses were assessed using the scores of Q3 and Q4 of the international index of erectile function (IIEF).Results : All three vardenafil doses showed significantly better improvement than the placebo group in Q3 and Q4 scores of the IIEF questionnaire, either at 12 weeks or at the 'last observation carried forward' (LOCF, P < 0.0001). Q3 scores were improved to 4.06 with vardenafil 5 mg, 4.53 with vardenafil 10 mg, and 4.64 with vardenafil 20 mg, versus 3.17 with placebo. Comparable scores for Q4 were 3.47, 4.15 and 4.31 versus 2.31 for placebo. Up to 86% of patients achieved improved erections as assessed by the global assessment question (GAQ). Reported adverse event rates were 35.3%, 45.3% and 54.5% with vardenafil 5 mg, 10 mg and 20 mg, respectively, versus 21.1% in the placebo group. No serious adverse drug reactions were reported. The most common treatment-emergent adverse events were transient headache, flushing and rhinitis, which were mostly mild. Conclusion : Vardenafil is an effective and well-tolerated treatment for ED and provides improvement in key indices of erectile function among Japanese men with ED. The results of our trial show that up to nearly 90% of patients achieve improved erections with the administration of vardenafil.

Vardenafil 20‐mg demonstrated superior efficacy to 10‐mg in Japanese men with diabetes mellitus suffering from erectile dysfunction

“…However, treatment option for difficult-to-treat ED patients, such as patients accompanying DM, has been limited in Japan, where high dose PDE5 inhibitors or intracavernosal injection/intraurethral injection of prostaglandin E1 are not approved, despite as many as 30% of ED patients failing sildenafil 50 mg. 13 Certainly, results of a phase IIb clinical study of vardenafil in Japan demonstrated its efficacy in wide range of ED population, but that study excluded enrollment of patients with DM. 15 So, it is quite important to evaluate if high doses of PDE5 inhibitor can offer the chance for difficult-to-treat ED patients, such as those with DM, to improve their erectile function. This study was planned as the first study in Japan to confirm better efficacy of high dose of vardenafil (20 mg) compared to the recommended dose of vardenafil (10 mg) in such a population with double-blinding settings.…”

“…The incidence of adverse drug reactions was not so different between 10 mg and 20 mg in this population, although vardenafil 20 mg showed slightly higher incidence of headache and flushing than 10 mg, which is consistent with the adverse event profile of a highly selective PDE5 inhibitor. 12,13,15,16 The majority of these events were mild in intensity and transient.…”

The Efficacy and Safety of Vardenafil in East Asian Men with Erectile Dysfunction

“…The first study, conducted between September 2001 and June 2002, assessed the safety and efficacy of vardenafil in the treatment of ED in men from Taiwan and South Korea (Taiwan, six centers; South Korea, seven centers). The second study, conducted between October 2000 and August 2001 in Japan (33 centers), has been reported previously [24]. After a 4‐week run‐in baseline period, patients were randomized to receive vardenafil (10 mg) or placebo for 12 weeks on an “as needed” basis, followed by a 7‐day follow‐up to collect safety information.…”

Pharmacotherapy for Erectile Dysfunction

“…Although side effects do occur with vardenafil (most notably headache, flushing, indigestion and nasal congestion), providing that the drug is used in line with the labeling recommendations, there is no convincing evidence in the literature of any significant safety issue, including cardiovascular, visual and aural safety [105–127].…”