Cylert (pemoline) is a CNS stimulant, which is structurally different from the amphetamines and Ritalin but acts like other known stimulants. Although studies indicate that pemoline may act in animals through dopaminergic mechanisms, the exact mechanism and site of action of the drug in man is not known.   Cylert has minimal sympathomimetic effects.

Because of its association with life threatening hepatic failure, Cylert is no longer considered a first line drug therapy for ADHD.  It is no longer available in the U.S.  Since 1975, at least 13 cases of acute hepatic failure have been reported to the FDA. While the absolute number of reported cases is not large, the rate of reporting ranges from 4 to 17 times the rate expected in the general population.