Megaloblastic anemia due to anticonvulsant therapy

Abstract

Megaloblastic anemia is a well-recognized but rare complication of long term treatment with phenobarbitone, phenytoin and primidone. Evidence of megaloblastic haemopoiesis is commonly seen in patients undergoing anticonvulsant therapy. A case of severe megaloblastic anemia complicating therapy with phenobarbitone and diphenylhydantoin sodium (phenytoin) is here described. Circumstantial evidence leaves little doubt that this patient initially had a megaloblastic type of anemia, although it is unfortunate that a diagnostic marrow examination was not performed. All epileptic patients on anticonvulsant therapy must be monitored for neurological, psychiatric and hematological deterioration, so that folic acid supplements may immediately be given if the deterioration, which often develops insidiously, can be traced to folate deficiency.