Carbamazepine-induced leukocytosis

An apparent case of carbamazepine-induced leukocytosis in a 26-year-old woman is presented. When admitted for psychiatric evaluation, the patient had been receiving carbamazepine for seizures for some time. A hemogram revealed a white blood cell (WBC) count of 21.2 x 10(3)/cu mm. Five days after the patient's medication was changed from carbamazepine (600 mg/day) to phenytoin (400 mg/day) and phenobarbital (120 mg/day), her WBC count was within normal range. When she experienced dizziness and ataxia, the phenytoin and phenobarbital were replaced with carbamazepine (600 mg/day). WBC counts performed 11 and 13 days after resumption of carbamazepine therapy again were significantly elevated. Other drugs administered during hospitalization included chlorpromazine, acetaminophen, and codeine. The possible causes of and pathophysiology of leukocytosis are reviewed. The changes in WBC that occurred with the rechallenge of carbamazepine indicate that the drug was the probable cause of the leukocytosis.