VIENNA, Austria - Abuse of prescription drugs is about to exceed the use of illicit street drugs worldwide, and the shift has spawned a lethal new trade in counterfeit painkillers, sedatives, and other medicines potent enough to kill, a global watchdog warned yesterday.

Prescription drug abuse already has outstripped traditional illegal drugs such as heroin, cocaine and ecstasy in parts of Europe, Africa and South Asia, the U.N.-affiliated International Narcotics Control Board said.

In the United States, the abuse of painkillers, stimulants, tranquilizers, and other prescription medications has gone beyond "practically all illicit drugs with the exception of cannabis," with users increasingly turning to them first, the Vienna-based group said in its annual report.

Unregulated markets in many countries make it easy for traffickers to peddle a wide variety of counterfeit drugs using courier services, the mail and the Internet.

"Gains over the past years in international drug control may be seriously undermined by this ominous development if it remains unchecked," Narcotics Control Board president Philip O. Emafo said.

Discount medications that seem to be authentic often turn out to be powerful knockoffs concocted from recipes posted on the Web.

"Instead of healing, they can take lives," Emafo said, characterizing the danger as "real and sizable."

Up to 50 percent of all drugs taken in developing countries are believed to be counterfeit, the board said, citing World Health Organization estimates.

Buprenorphine, a painkiller, is now the main injection drug in most of India, and it also is trafficked and abused in tablet form in France, where the Narcotics Control Board estimates at least 20 percent of the drug sold commercially as Subutex is diverted to the black market.

The number of Americans abusing prescription drugs nearly doubled from 7.8 million in 1992 to 15.1 million in 2003, the Narcotics Control Board said.

Among their prescription drugs of choice: the painkillers oxycodone, sold under the trade name OxyContin, and hydrocodone, sold as Vicodin and used by 7.4 percent of college students in 2005.

Although the number of U.S. high school and college students abusing illicit drugs declined in 2006 for a fourth consecutive year, "the high and increasing level of abuse of prescription drugs by both adolescents and adults is a serious cause for concern," the report said.

Counterfeiters are exploiting intense demand for prescription drugs that can give a high comparable to cocaine, heroin or methamphetamine, the watchdog group said.

It singled out Scandinavia, where demand for flunitrazepam - a sedative sold as Rohypnol and widely known as a "date-rape drug" - increasingly is being met by unauthorized production, and North America, where widespread abuse of prescription drugs, including the narcotic fentanyl - 80 times as potent as heroin - has been blamed for a spike in deaths.

"The very high potency of some of the synthetic narcotic drugs available as prescription drugs presents, in fact, a higher overdose risk than the abuse of illicit drugs," Emafo said.

Exact figures were unavailable, he said, because few countries "are aware to what extent drugs are being diverted and abused" and are not tracking the trend. Nations should pay closer attention and share data on counterfeit drug seizures, the group urged.

Other findings in the report:

Cultivation of opium poppy in Afghanistan hit a record high last year, an assessment also made by other agencies.

Iran is now the world's No. 1 abuser of opiates, and 2.8 percent of the population uses illicit cocaine and heroin, most of it from Afghanistan.

Bolivia plans to introduce a drug-control policy that would broaden the marketing and use of coca leaves - a step the Narcotics Control Board warned could violate international drug conventions.

Read from the global

drug report, including a breakdown by region, via http://go.philly.com/drugtrade EndText