potential, pemoline is listed as schedule IV (non-narcotic). In studies conducted on primates, pemoline fails to demonstrate a potential for self-administration. It is thought to have little potential for abuse and dependence. Nonetheless, misuse may theoretically occur owing to its similarity to other psychostimulants. Pharmacokinetics Studies of the pharmacokinetics of pemoline in humans are very limited. The time to peak levels of pemoline is 2 to 4hours. Peak levels have been reported to be in the range of 2 to 4.5μg/mL. Steady-state levels of pemoline are reached in 2 to 3days. Pemoline is variously reported to have no significant plasma protein binding or to have 50% plasma protein binding. Pemoline is metabolized in the liver. Its metabolites include pemoline conjugate, pemoline dione, mandelic acid, and unidentified polar metabolites. Pemoline is excreted mainly by the kidneys with around 50% excreted in unchanged form and only minor amounts present as metabolites. The elimination half-life of pemoline is 7 to 12hours. The half-life is 7hours in children but may increase to 11 to 12hours with age. The relatively long half-life of pemoline allows for once-daily administration. No differences in the pharmacokinetics of pemoline were found with conventional tablets, chewable tablets swallowed, or chewable tablets chewed. Chemistry Pemoline is a member of the 4-oxazolidinone class and is structurally related to other members of the class including aminorex, 4-methylaminorex, clominorex, cyclazodone, fenozolone, fluminorex, and thozalinone. The salts of pemoline in use are pemoline magnesium (free base conversion ratio .751), pemoline iron (.578), pemoline copper (.644), pemoline nickel (.578), pemoline rubidium, pemoline calcium, pemoline chromium, and chelates of the above which are identical in weight to the salt mentioned. Pemoline free base and pemoline cobalt, strontium, silver, barium, lithium, sodium, potassium, zinc, manganese, and caesium are research chemicals which can be produced in situ for experiments. Others such as lanthanide pemoline salts such as pemoline cerium can be prepared; pemoline beryllium would presumably be toxic. History Pemoline was first synthesized in 1913 but its activity was not discovered until the 1930s. Pemoline was approved for the treatment of ADHD in the United States in 1975. Cases of serious liver toxicity and associated death related to pemoline in children and adolescents were reported to the United States Food and Drug Administration's MedWatch between 1977 to 1996. Serious liver toxicity with pemoline was first described in the medical literature in 1984 and 1989 letters to the editor. Clinicians