Pemoline-induced abnormal involuntary movements

Plasma pemoline levels were measured in 6- to 12-year-old, severely hyperactive males coincident with onset of abnormal involuntary movements. Acute exposure to pemoline (2 mg/kg orally) was associated with choreoathetoid movements of face, limbs, and trunk in five of 20 subjects in an acute study of pemoline pharmacokinetics. Also reported is a series of four chronically treated patients who developed choreiform movements and dyskinesias after variable periods of exposure from 3 weeks to 3 months with pemoline (1.5-2.0 mg/kg/day). Abnormal movements following acute or chronic exposure to pemoline cleared after pemoline discontinuation. Pemoline pharmacokinetics does not seem to be a primary determinant in the development of abnormal involuntary movements after chronic exposure. Total amount of pemoline absorbed may play a role in the development of choreoathetoid movements following acute exposure.