Levitra: New Impotence Drug Christened
Like Viagra, Levitra 'Amplifies' Small Erections
Both Viagra and Levitra work by inhibiting the PDE5 enzyme. "That means that if you take a pill, then have sexual stimulation, the drug can magnify the natural erectile response. It allows the reaction to be more like sex should be."
The biochemical differences between the two drugs mark the difference, he says. "Levitra contains a more efficient enzyme inhibitor, so only a very small amount of the drug is necessary," Goldstein tells WebMD. "That's the thing that's cool about Levitra -- it's biochemical potency is distinctly different from Viagra and Cialis [another impotence treatment drug being developed by Lilly]."
All three drugs -- plus several more still in development -- have their place in a physician's armamentarium, says Goldstein. "Several other companies are also working on drugs with PDE5 inhibitors."
When it starts to work and how long it lasts are big issues in impotence medicine: Viagra takes effect in about 30 minutes and the effects last about 4 hours. Cialis reaches maximum concentration in 24 hours, and the effects last for about 3 days, says Goldstein. Levitra is faster-acting, reaching maximum concentration in 30 to 40 minutes, with the effects lasting about 16 hours.
Also, Levitra doesn't carry one disconcerting visual problem that many men report with Viagra: "If you take Viagra, you get a weird blue vision," he says.
Just don't expect miracles with Levitra, says Lipshultz.
"The strength of the drugs will probably be comparable -- they're all supposed to inhibit the enzyme PDE5," Lipshultz tells WebMD. "Whatever dose you take inhibits it completely. So I don't think we're going to be seeing a whole lot of advertising based on 'take this drug because it's stronger.'"
Also, if you didn't have success with Viagra, it's doubtful that Levitra will work any better, says Lipshultz. "I don't think we're going to see people who fail one drug do a whole lot better on another drug. I think where the difference will be -- if any -- is onset of action, duration of action, and side effects."