MONDAY, May 31 (HealthDay News) -- Internet-based companies market them, men continue to buy them and experts continue to warn of the dangers of counterfeit drugs for erectile dysfunction.
A new study, conducted in South Korea and slated for presentation Monday at the American Urological Association annual meeting in San Francisco, finds that not only can these knock-off drugs be contaminated, they may contain too much of the active ingredient or none at all.
The drugs could especially be dangerous for men with hypertension or heart disease, the study found.
The message? Stay away from non-prescription erectile dysfunction (ED) drugs, the experts say.
"There are lots of rip-offs," said Dr. John Morley, director of geriatrics and acting director of endocrinology at Saint Louis University. "There's still a lot of evidence that many of the things you buy off the Internet without going through a regular pharmacy might appear cheaper or better but they're usually not and they usually don't work."
Drugs known as phosphodiesterase type 5 inhibitors (PDE5Is) are used widely by men with erectile dysfunction - and sometimes by those without the condition. Perhaps the best known of the class are sildenafil (Viagra) and tadalafil (Cialis). Since it was developed in 1998, the market for these and similar products -- legitimate or not -- has mushroomed.
ED drugs are sort of in a special class, given the personal nature of the problem and many men's reluctance to discuss it, even with a doctor.
"Men who have sexual dysfunction are prepared to try anything and they do try a large number of bizarre things," said Morley. "They try all the Viagra look-alikes, so people are going to buy them."
In the study, the South Korean team compared 19 counterfeit erectile dysfunction (ED) drugs against prescription Viagra, obtained directly from Pfizer Pharmaceuticals, and Cialis, provided by Lilly.
About one-third of the counterfeit pills actually differed in size from the real thing, while 42 percent differed in color.
Fifty-eight percent had too much active ingredient, sometimes as much as 2.4 times more, while 3 percent had no active ingredient at all.
Some contained unapproved compounds intended to promote an erection.
Only one of the counterfeit drugs contained "proper active ingredients," the researchers stated. Some contained potential toxins, including mercury and lead.
Even genuine Viagra has risks, experts note, especially for men who take nitrates for chest pain. And there could be drug interactions with both real and fake ED drugs.
"All these drugs have side effects and that's probably the big reason why patients should be getting them through a physician," Morley said. "While these things may be cheaper, they potentially have much greater side effects."
"We would hope by now that men would be happy to talk to their doctor [but] fundamentally, people are still shy of this," he continued.
There's more on counterfeit medications at the World Health Organization.