The US Food and Drug Administration has just approved vardenafil, a new drug for erectile dysfunction. The drug, to be marketed as Levitra, is to be launched with a high profile advertising campaign using top US sports stars.
The FDA's approval was based on more than 50 trials involving over 5700 men that compared vardenafil with placebo. Men taking vardenafil were on average five times more likely to achieve an erection that sustained intercourse than men taking a placebo, the results of these studies showed. Vardenafil worked in 86-92% of men studied, an FDA press release says.
GlaxoSmithKline, the US distributor of vardenafil (which is made in Germany by Bayer) has hired sports stars as spokesmen to promote the product and capture market share. It seems to be taking its cue from Pfizer (which makes sildenafil (Viagra)), which has a current television advertisement featuring Rafael Palmeiro, a baseball star, as the company's spokesman. GlaxoSmithKline has joined with the National Football League in a campaign that seeks to lift the taboo on speaking about erectile dysfunction. The campaign will use Mike Ditka, a famous football coach, as its spokesman.
Additionally, although vardenafil is not approved for use by women, the advertising will also target women, encouraging them to seek help for their male sexual partners.
A third drug for erectile dysfunction, tadalafil (Cialis), developed by Eli Lilly, is expected to reach the US market later this year. Both vardenafil and tadalafil are already available in some countries of Europe and in South Africa.
Vardenafil, which is available in 2.5-20 mg doses, works in a similar manner to sildenafil but has a quicker onset and a longer duration of action, according to Bayer, which claims that the drug works within 16 minutes and its effects last as long as five hours.
In contrast, sildenafil takes between 20 and 60 minutes to work and its average duration of action is four hours. Despite these claims, so far no trials have directly compared the two drugs. Both drugs should be taken an hour before sexual activity.
Like sildenafil, vardenafil is a phosphodiesterase-5 inhibitor and has similar cardiac side effects. It is contraindicated in people with low blood pressure as well as those taking nitrates and a blockers. Additionally, vardenafil, like sildenafil, should not be used by patients who have had a recent myocardial infarction, stroke, or retinitis pigmentosa.
Side effect profiles are also similar to those of sildenafil and include nasal congestion, headache, flushing, and dizziness. Vardenafil may, however, cause a prolongation of the QT interval and increase the potential for re-entrant cardiac arrhythmias—a potentially dangerous side effect that is not seen with sildenafil.