Isoniazid induced pellagra despite pyridoxine supplementation

Abstract

Although pellagra is a recognized complication of isoniazid therapy, the diagnosis may be overlooked or delayed--sometimes with life-threatening consequences. We report a case of isoniazid-induced pellagra which occurred despite pyridoxine supplementation. Drug withdrawal and supplementation with niacin led to a rapid and sustained clinical improvement. The possible mechanisms of isoniazid induced pellagra are discussed.