A US Food and Drug Administration (FDA) analysis of three commonly prescribed drugs purchased from a Web site advertised as Canadian showed that so-called "Canadian Generics" bought from the Web site were fake, substandard and potentially dangerous. One was a controlled substance. In light of these findings, FDA reiterates its strong concerns about purchasing prescription drugs online from unknown sources, a FDA release said.

FDA investigators recently purchased three commonly prescribed drugs from a Web-site advertising "Canadian Generics," which had been sending "spam" emails promoting its products. The products purchased were so-called "generic" versions of Viagra, Lipitor, and Ambien. None of the three products has a US-approved generic version, and so all three drugs were unapproved.

"The test results of our analyses offer proof positive that buying prescription drugs online from unknown foreign sources can be a risky business. As was the case here, even where a website looks legitimate, FDA has clear evidence that the Web site is dispensing misbranded drugs that are not the same quality as those approved by the FDA for sale in the United States. Consumers who believe they are getting equivalent products from reputable sources are being misled and putting their health at risk," said FDA acting commissioner Dr. Lester M Crawford. "This firm shipped drugs that were the wrong strength, including some that were substantially super-potent and that pose real health risks as a result, drugs that didn't dissolve properly, drugs that contained contaminants, and drugs that should not have been given because of potentially dangerous drug interactions," he added.

Ambien, a controlled substance (schedule IV), is approved for the short-term treatment of insomnia in the US. The product FDA obtained online contained too much active ingredient, including one tablet that was nearly double the labelled potency. Taking "superpotent," Ambien puts patients at risk for central nervous system depression, especially in elderly or debilitated patients.

The so-called "generic" Lipitor FDA purchased was subpotent and failed standard dissolution tests, providing on average only 57 per cent of the active ingredient claimed on the label. It also failed FDA's purity testing. Clinically, subpotent product could present a long-term risk for the various complications of high cholesterol, such as heart disease. In addition, the so-called "generic" Lipitor product was furnished to FDA's online purchaser, even though the purchaser said that he was taking the antibiotic Erythromycin. Lipitor's label warns against taking Lipitor and Erythromycin at the same time.

The so-called "generic" version of Viagra also contained too little of the active ingredient, failed the dissolution test, and had an unacceptable level of impurities. Although subpotent "generic" Viagra may not place patients at additional risk, the purchaser informed the firm in its on-line questionnaire that he was taking Erythromycin. Use of Viagra in patients taking Erythromycin is contraindicated.

FDA continues to advise patients and consumers that they must use great care when purchasing prescription drugs online. This evidence indicates that although a Web site may appear to be hosted by a reputable source and may look similar to other retail pharmacy Web sites, many of these sites in fact operate from outside the United States and are providing unapproved drugs from unreliable sources. The National Association of Boards of Pharmacy (NABP) has established a program called VIPPS designed to certify Web sites that meet industry standards. The Agency believes that consumers should look for participation in this type of certification program as one method to help minimize the risks of getting bad quality drugs from disreputable sources, the FDA release says.