Seizures following reduction in phenytoin level after orally administered folic acid

Abstract

Phenytoin reduces folate levels and may be responsible for the development of a macrocytic anemia. This may be avoided by prophylactic administration of folic acid to patients with seizure who will be on long-term anticonvulsant treatment. The relationship between folate and phenytoin metabolism, however, is a dual and interdependent one and the addition of folic acid to a stable anticonvulsant regimen predictably lowers serum phenytoin levels.1 We report a case of recurrent seizures in a patient after the addition of folic acid for treatment of macrocytic anemia. The reduction in drug levels was substantial and resulted in several seizures in a patient previously well controlled. A 52-year-old man was admitted to the hospital for repair of an acute hip fracture. There was a history of cerebrovascular disease complicated by stroke, hemiparesis, and generalized tonic-clonic seizures. He had been free of seizures for the 3 years previous to …