Intoxication with Primidone: Continuous Monitoring of Serum Primidone and its Metabolites during Forced Diuresis

Abstract

An 18 yr old girl is reported, who ingested 15 g of primidone (Liskantin), 330 mg/kg, to commit suicide. Continuous monitoring of the serum levels of primidone, PEMA [phenylethylmalonamide] and phenobarbital revealed increased elimination of primidone by forced diuresis (6000 ml/24 h). Forced diuresis inhibits the otherwise mandatory increase in primidone metabolites, PEMA and phenobarbital. It is suggested that even after improvement of the clinical symptoms forced diuresis should be continued for at least 48 h. In epileptic patients the reinstitution of primidone therapy should be considered only on the 3rd day after accidental ingestion, if the clinical symptoms have improved, and if there is no possibility of immediate determination of primidone serum levels.