Phenylethylmalonamide Serum Levels in Patients Treated with Primidone and the Effects of Other Antiepileptic Drugs

Abstract
Data are presented for the serum levels of 2-ethyl-2-phenylmalonamide (PEMA) in patients receiving anticonvulsant medication. Statistical analysis of these data indicates that the serum level of PEMA, which is a metabolite of primidone, is affected not only by the dose of primidone but also by the serum levels of other prescribed anticonvulsant drugs. In particular phenobarbitone is shown to be a major perturbation upon the PEMA serum level.