Cylert or pemoline, made by Abbott Laboratories, for the treatment of attention deficit hyperactive disorder (ADHD) should be taken off the market immediately because of its risk of liver toxicity, a consumer advocay group wrote in a petition to the Food and Drug Administration.

At least 21 cases of liver failure, including 13 resulting in liver transplantation or death, have been reported since Cylert was approved in 1975, according to Public Citizen.

In the March 24, 2005 petition, Public Citizen said Cylert has no demonstrated unique therapeutic benefit over other ADHD drugs such as methylphenidate. The group also cites how Cylert’s unfavorable risk to benefit ratio prompted its withdrawal in the Britain and Canada.

“In light of this evidence of unique liver toxicity without evidence of unique therapeutic benefit, we contend that the only responsible course of action is to remove this dangerous drug from the market,” the petition stated.

The FDA considered the withdrawal of the drug, but instead elected to allow sales of Cylert as long as Abbott made a good faith effort to gather more safety data and the label was changed, the petition stated. However, Abbott failed to carry out the prospective patient registry that was a condition’s for the drug’s continued marketing. The labeling changes made have had no measurable effect on ensuring safe use of Cylert, the petition contends.

(via Public Citizen)