The U.S. Food and Drug Administration said Thursday it stands by its warning to Americans not to buy drugs from a Manitoba-based internet pharmacy, claiming the drugs are counterfeit.

The FDA issued a news release on Wednesday warning against ordering 10 specific prescription drugs from 10 websites, including rxnorth.com, canadiandrugstore.com and canadian-safe.com.

Those orders are filled via Mediplan Prescription Plus Pharmacy or Mediplan Global Health of Minnedosa, Man.

Andrew Strempler of Mediplan said Wednesday his company regularly tests the drugs it sells and they are safe and reliable.

But Dr. Randall Lutter, the FDA's associate commissioner of policy and planning, said Thursday the U.S. government has seized thousands of shipments of drugs destined for American customers.

The FDA tested those drugs and found they are counterfeit, Lutter said, meaning they weren't made by recognized manufacturers and don't contain the correct concentrations of drugs.

No evidence of contaminants

"It's important to say that these are only what we've seized to date," Lutter said.

Lutter warned Americans who may be buying any of the 10 drugs listed from Mediplan — including popular remedies such as Lipitor and Celebrex — that they may not be getting what they asked for.

"They're being defrauded, they are being exposed potentially to contaminants; they're not getting the active ingredient that their doctor ordered and therefore they're not getting the therapeutic benefit," he said. "That's our key message."

However, Lutter said, the FDA has found no evidence of contaminants in the drugs.

He said the agency is continuing to test the seized drugs and the list of drugs the FDA is warning Americans not to order from Canadian internet pharmacies may grow.

The FDA's warning notes that earlier seizures of prescription drugs from Canadian internet pharmacies found that 85 per cent of drugs advertised as "Canadian" came from 27 other countries.

Consumers should do research

The group representing Canadian internet pharmacies said the FDA's role is not to be a scaremonger to Americans.

John Myers, secretary and general counsel for the Canadian International Pharmacy Association, said Thursday the agency's move was just another attempt by American interests to discredit Canadian internet pharmacies.

The FDA has not defined what it meant by "counterfeit" and has no real evidence to support the allegation, he added.

Myers stressed that consumers should always do their research about drugs they're prescribed and the FDA should do a better job of helping them.

"I think it's appropriate for a regulator to educate, but I think it's inappropriate for a regulator to scaremonger and say, 'Well, we have some allegations here, therefore you ought not to be buying your prescription drugs from outside the country,' " Myers said.

"That simply just protects their domestic drug industry from competition and that's not really the role of a regulator, in my view."

With files from the Canadian Press