They analyzed samples of Viagra sold on the Web and found that some
of the little blue pills contained different components or less of the
active ingredient than the top-selling drug made by pharmaceutical giant
Pfizer Inc.
"On our initial estimate, around half of those Viagra samples could
be counterfeit," Dr Nic Wilson, of the University of London, told the
British Pharmaceutical Conference.
Viagra, which works by allowing more blood-flow to the penis during
sexual arousal, is a lifestyle drug along with hair-loss and weight
treatments. All are widely available on the Internet and major targets
for counterfeiters.
With impotence, or erectile dysfunction (ED), affecting about 152
million men worldwide, there is a huge market for the treatment. It is
estimated that half of all men over 40 experience some degree of ED,
which increases with age. About 95 percent of cases can be successfully
treated.
The bogus drugs were branded and labeled Viagra and came in identical
packaging to the real thing.
"What we are talking about is somebody selling something as Viagra
which is clearly not made by Pfizer," Wilson's colleague Professor Tony
Moffat said in a telephone interview.
The scientists are not sure whether wrong components in the bogus
pills are harmful, but at the very least it is highly probable the fakes
will not work.
If the counterfeiters get the dose wrong and the bogus pills contain
too much of the active ingredient, sildenafil, it could be dangerous.
"Part of the side reaction of the sildenafil is increased heart
pressure, so people could get heart attacks," Moffat added.
"If you go to a site that looks a bit wonky, they are selling it
cheap and you've got no address or idea where they are based, you are
chancing it."
Wilson and Moffat used a technique called near infrared (NIR)
microscopy which provides a more detailed picture of what is in a tablet
and its active ingredients to separate the fakes from the real thing.
The researchers tested the technique on known counterfeit Viagra
before using it on pills they bought on the Internet. Pills arrived from
a variety of countries including Thailand, India and Malta.
Eventually they believe the technology will be able to track the
counterfeit products across the world.
