Oral Therapy for Impotence Vardenafil (Levitra) for erectile dysfunction. The Medical Letter 2003;45(1166):77-78.

Vardenafil, like sildenafil, is a selective phosphodiesterase type 5 inhibitor approved by the FDA for treatment of erectile dysfunction. A third drug, tadalafil (Cialis), which has not been approved by the FDA, but is available in Europe and on the Internet, is supposed to have a longer duration of action. No studies are available that directly compare the time of onset, duration, or effectiveness of vardenafil and sildenafil.

Vardenafil can cause a slight prolongation of the electrocardiogram QT interval and should not be taken concurrently with antiarrhythmic drugs such as quinidine, amiodarone, or sotalol. Vardenafil, like sildenafil may potentiate the hypotensive effects of nitrates and alpha-blockers; its labeling contraindicates use in patients taking these drugs. Levitra is marketed in 2.5, 5, 10, and 20 mg tablets, with the recommended starting dose 10 mg taken with or without food about 60 minutes before sexual activity. It is effective for men about 50% to 80% of the time. There is no evidence that vardenafil has a shorter onset of action or any other advantage over sildenafil.