The FDA recommends that doctors who prescribe Cylert or any generic versions of the drug (pemoline) switch patients to another therapy.
The risk of liver failure outweighs the drugs' benefits, says the FDA in a news release.
Warning Isn't New
Warnings of possible liver problems with Cylert and its generic versions aren't new.
Discontinued for Commercial Reasons
Cylert's maker, the drug company Abbott, chose to discontinue sale of the drug in May for financial reasons.
"The sales of the drug at the time were less than $1 million dollars anticipated for 2005, and so we discontinued it for commercial reasons," Abbott spokeswoman Jennifer Smoter tells WebMD.
All generic companies have also agreed to stop sales and marketing of the drug, the FDA notes.
"The usage of pemoline, which is the generic name for Cylert, has been declining over the years," says Smoter. "There were a number of generic alternatives at the time."
"Cylert has been a second-line treatment for ADHD for a very long time, since the late 1990s," says Smoter. "It's been on the market for 20-plus years."
Cylert will remain available through pharmacies and wholesalers until supplies are exhausted. After that, it won't be available.
That plan was put in place when Abbott discontinued Cylert in May. "People did need ample time to be able to transition to an alternative therapy," says Smoter.
Liver Problems Cited
The FDA says it's aware of 13 reports of liver failure resulting in liver transplant or death, usually within four weeks after the onset of signs and symptoms of liver failure.
One case occurred after the drugs started carrying the boxed warnings in 1999, the FDA notes.
Thirteen isn't a huge number, but the rate of liver failure in people taking pemoline is "10 to 25 times greater" than that of the general public, states the FDA.
"The cases that were cited by FDA were not new," says Smoter.
Report Side Effects
The FDA asks that any unexpected or serious side effects from Cylert and generic pemoline products be reported to its MedWatch program.
The FDA's MedWatch program can be reached by phone at (800) FDA-1088 ((800) 332-1088) or online at www.fda.gov/medwatch/report/hcp.htm.