Carbamazepine and erythroid arrest.

A patient who developed anemia with an isolated erythroid toxicity following chronic carbamazepine administration is reported. The anemia quickly resolved with discontinuation of this drug. Other hematologic toxicities of carbamazepine are well described; however, an isolated erythroid toxicity is unusual. In addition, the onset of this drug-induced toxicity developed later than is expected for carbamazepine-associated hematological toxicities. This case demonstrates the suddenness with which hematological toxicities can occur with carbamazepine, and affirms the need for regular monitoring of patients. Any significant decrease in the patient's hemoglobin or hematocrit level requires close monitoring for the sudden development of serious anemia.