These sites also do not require a prescription to buy the drugs and none of them has controls to prevent children from making such purchases, say the authors of the report released Wednesday by the National Center on Addiction and Substance Abuse at Columbia University.
The report, titled "'You've Got Drugs!' V: Prescription Drug Pushers on the Internet," says that nearly all the Web sites do not ask Internet users for a proper prescription from a doctor while many of then openly state that no prescription is needed.
The report, which tracks the availability of powerful pain killers like morphine and oxycodone and stimulants such as amphetamine, is the fifth annual report on the subject issued by the Columbia group.
According to the Drug Enforcement Agency, about 80 percent of all online prescriptions are for controlled substances, compared with just 11 percent of prescriptions filled at traditional pharmacies. Nearly 85 percent did not require a doctor's prescription, the report said.
Federal law prohibits sales of dangerous medications without a prescription from a doctor who has a bona fide relationship with the patient. However, with the advent of Internet it easy for drug dealers to ship the drugs from foreign countries in disguised packages.
According to a 2005 survey, nearly one in five teenagers has abused prescription drugs in their lifetime. Most Internet users are adolescents and young adults; 78 percent of children aged 12 to 17 have online access.
The U.S. Senate passed the Ryan Haight Online Pharmacy Consumer Protection Act in April which requires certification of online pharmacies and that doctors see patients before prescribing controlled drugs.
The bill is now in committee in the House.


