Francis Palumbo of the University of Maryland School of Pharmacy, the author of the report, "Policy Implications of Drug Importation," said U.S. consumers face a growing risk of getting counterfeit drugs because of rising Internet sales of medical drugs -- projected to reach upwards of $75 billion by 2010.

"When consumers buy from those, it is definitely buyer beware. They are often not licensed anywhere we are aware of," Palumbo said in a statement.

The U.S. Food and Drug Administration "has been pulling its hair out over the years trying to deal with rogue Internet sites, the terminology they (FDA) use," he said.

During the past 10 years, many people have been importing prescription drugs that were available for purchase in the United States and justifying the foreign purchases based on the FDA's policy of personal use exemption, Palumbo said.

"The policy was never intended to allow this practice to be institutionalized," the report says.

The report concludes that both FDA and U.S. Customs officials can't handle the volume of medication entering the country.

The report is published in the journal Clinical Therapeutics.