Appropriate use of carbamazepine for the treatment of epilepsy is based on correct identification of the patient's seizure type. Carbamazepine is effective against partial seizures and against generalized tonic clonic seizures. Therapy should begin gradually, with initial doses increased slowly over 1 or 2 weeks, as tolerated. Side effects include fatigue, dizziness, ataxia, double vision, nausea, and vomiting. Most practitioners agree that, because of carbamazepine's relatively short half-life, the total dosage should be administered in at least two divided doses. This avoids too high a peak blood level that would occur with a single dose. Carbamazepine therapy is associated with the development of two hematologic conditions. Leukopenia, which may be transient or persistent, requires careful monitoring but is not cause for immediate discontinuation of therapy. Aplastic anemia occurs rarely but is potentially fatal, and therefore diligent monitoring of hematologic function is indicated. Aplastic anemia is an idiosyncratic, non-dose-related side effect that is most likely to occur within the first 3 or 4 months of initiating therapy. Once seizures are controlled, plasma levels of carbamazepine should be measured to establish optimum levels for individual patients being treated with this drug.