WASHINGTON -- Once a problem mainly in developing countries, counterfeit medicine is increasingly turning up in the United States, prompting federal health officials to hunt new ways to keep the nation's drugs secure.
Since March, the Food and Drug Administration has begun investigating six counterfeit drug cases -- from a psychiatric pill replaced with aspirin to anemia injections that delivered doses 20 times lower than patients were supposed to get.
The sudden spate is in addition to three still-unsolved cases last year.
There is some good news: New York prosecutors last month announced a big crackdown, charging seven people and five companies with counterfeiting Viagra, the wildly popular little blue impotence pill. Some of the pills had a little of the drug, some had none. The nine-month investigation unraveled a sophisticated ring that stretched from fake pill mills in China and India to Internet sellers in Nevada and Colorado.
But "the protected nature of America's pharmaceutical supply is being eroded somewhat," said Lewis Kontnik of Reconnaissance International, a consulting firm that specializes in anti-counterfeiting measures.
A big reason for the spate is little oversight of Internet drug sales, he says. Another may be the popularity of performance-enhancing drugs, because some of the newest, priciest counterfeits include complex muscle- and blood-boosting products, he says.
"There is a real intrusion of counterfeits into the U.S." that requires action to ensure the problem doesn't grow, adds Kontnik. His company is hosting an international meeting in September where FDA, pharmaceutical companies and anti-counterfeiting experts will debate how to tackle fake drugs.
Monitoring and fighting counterfeiting is made more difficult for FDA because drug companies aren't required to notify the agency of all counterfeit cases -- rules that are about to change. Nor do they often share what security measures they use.
"It's time for the agency and industry to attack this issue together," says FDA lawyer Benjamin England.
He is finalizing plans to create a confidential program where drug makers, security companies and regulators would share what anti-counterfeiting technologies work best for different drugs, and search for new ways to spot fakes before they sell.
But Pfizer Inc., which has aggressively fought fake Viagra for years, says a chief deterrent may turn out to be headline-making arrests -- until now rare.
Prosecutors are "starting to get very aggressive, recognizing this could be potentially a public health issue," says Pfizer's Geoff Cook.
Counterfeit drugs -- a term encompassing outright fakes and tampering with real medicines -- have long been epidemic in parts of the world. One recent study found a third of malaria pills sampled in parts of Asia contained no trace of the real medication.
There's no good data on how often counterfeits sell here, where pharmaceutical regulation is the world's strictest. But experts say while the vast majority of U.S. drugs are fine, the recent spate does suggest a rising problem.