Phensuximide is an anticonvulsant. It inhibits seizures induced by maximal electroshock (MES) and pentylenetetrazole in mice (ED50s = 112 and 50 mg/kg, respectively). Phensuximide (1.25 mmol/kg, i.p.) induces proteinuria and hematuria in rats. Formulations containing phensuximide have been used in the treatment of petit mal seizures.