Viagra, OxyContin and some AIDS drugs will be among the first to carry radio chip tracking devices under a new Food and Drug Administration initiative to prevent theft and counterfeiting announced on Monday.

The FDA said it was lifting restrictions on labeling that may have discouraged companies from testing out the little antennas, which can be used to trace drugs from factory to pharmacy.

“In recent years, bogus medications have become a growing public health threat because of counterfeiters’ ability to infiltrate our drug distribution system with worthless counterfeits,” FDA acting commissioner Dr. Lester Crawford told reporters in a telephone briefing.

Viagra, Pfizer’s blockbuster impotence drug, has been especially targeted by counterfeiters and copycats, while privately owned Purdue Pharma says theft is its primary concern in tagging OxyContin, a narcotic notorious among abusers.

And GlaxoSmithKline said several of its drugs, including AIDS medications such as Combivir and Epivir, would get tags within the next 12 to 18 months.

The chips, called radio frequency identification or RFID tags, can be attached to packaging to track products or check their authenticity.

“We are providing guidance today to assure companies that if they do do this tagging, that they won’t be violating our labeling regulations,” said William Hubbard, the FDA’s assistant director for policy planning.

“In some technical fashion they might have been concerned,” he added. “You need someone to step forward and exert leadership. There are many examples where technology could produce benefits but people were afraid to jump in.”

SAFETY THREAT

Counterfeits pose a real safety threat to patients, said Thomas McGinnis, FDA’s deputy associate commissioner of health affairs.

“We have seen injections that were nothing more than tap water that were contaminated with bacteria.

We worry about impurities,” McGinnis told reporters, predicting that radio tags would eventually replace bar codes on drug products.

The FDA has been working with industry for more than a year to try to come up with ways to better protect drugs and foil counterfeiters.

The technology is already being tested by retailers such as Wal-Mart Stores Inc. to track goods and signal when restocking is needed with scanners in warehouses, back rooms and stores.

Britain’s Marks & Spencer Plc, Germany’s Metro AG and fellow U.S. discount store Target Corp. are also testing the concept.

No. 1 drugstore chain Walgreens said it would start using the chips.

The FDA says fewer than 1 percent of prescription medicines sold in the United States are fake. But the agency says counterfeiting is becoming more common and criminals are using more sophisticated techniques.

Aaron Graham, chief security officer at Purdue, said individual bottles of OxyContin would be labeled and will allow the company to precisely track each bottle of the narcotic. “We are shipping this week,” Graham said in a telephone interview.

“We have color-shifting ink incorporated into the label so pharmacist can look at the bottle and tilt it and see it go from green to purple say. ‘That’s Purdue’s bottle’,” he added.

But crime was the biggest factor, Graham said.

“Right away, for the first time ever, a cop can say ‘that bottle came from a crime scene and this suspect is in possession of stolen property’,” Graham said.

“We are going to implement RFID as a deterrent.”