March 1st 2003
Vardenafil (Levitra, Bayer AG/GlaxoSmithKline) is a selective inhibitor of phosphodiesterase 5 (PDE5) currently under review by FDA for the treatment of erectile dysfunction (ED). If approved, vardenafil will become the third PDE5 inhibitor to be marketed in the United States and the fourth oral agent approved for the treatment of ED. Vardenafil has been studied in subjects of various ages (<45 and >65 years of age), with different etiologies and different baseline severity of ED. Studies evaluating vardenafil have determined it to be safe and effective at doses of 5 mg to 40 mg, including subjects with diabetes mellitus and subjects who have undergone radical prostatectomy. Vardenafil has a pharmacokinetic profile similar to that of sildenafil (Viagra, Pfizer). The drug appears to be well tolerated. In clinical trials, headache, dyspepsia, and flushing were the most common adverse effects reported by subjects taking vardenafil. No adverse hemodynamic or visual effects have been reported during clinical trials of vardenafil; however, further investigation, including post-marketing surveillance, will be required. Further research and clinical experience with the newer PDE5 inhibitors (vardenafil and tadalafil [Cialis, Lilly/ICOS]) will be needed before their roles in the treatment of ED can be determined.