According to the U.S. Food and Drug Administration, liver problems linked to the attention deficit drug Cylert and other generic versions of the drug make it too dangerous for the U.S. market.
FDA officials have stopped short of recalling the drug, which has been on the market since 1975, but are advising doctors who prescribe it, or its generic counterparts to seek alternative therapy for their patients.
In a warning posted on its web site the FDA says it has concluded that the overall risk of liver toxicity from Cylert and generic pemoline products outweighs the benefits of the drug.
The agency says Cylert will remain available until current supplies run out, which has angered consumer advocates who argue that the drug is too dangerous.
Earlier this year drug company Abbott said it would no longer make the 30-year-old drug due to declining sales, and generic makers also agreed to stop sales.
Laureen Cassidy, a spokeswoman for Abbott, says the decision to discontinue Cylert was based on commercial reasons as demand for pemoline products has declined significantly over the years.
The FDA says it received 13 reports of liver failure that led to patient death or an organ transplant, and the rate involving patients taking pemoline was 10 to 25 times higher.
The fact that there are "multiple other drug treatments" for Attention Deficit Hyperactivity Disorder, or ADHD, apparently aided the agency's decision.
However Public Citizen's Health Research Group Director Sidney Wolfe, which filed a petition with the FDA in March calling for the drug's withdrawal, said the new warning did not go far enough and urges a total recall.
He maintains the use of the drug is reckless and insensitive to the health and lives of children and adults.
Wolfe says a uniquely dangerous is basically being sold off until it runs out. He says about 10,000 Cylert prescriptions have been sold since it was discontinued, while around 50,000 generic prescriptions have been filled.
The FDA's warning is posted online.