Long-term response to carbamazepine: a retrospective study.

Carbamazepine is now used by many clinicians in the treatment of bipolar disorder (BD) refractory to standard treatments, including lithium and neuroleptics. Little information is yet available about the utility and efficacy of this novel treatment during long-term use. We carried out a retrospective study of 50 patients (34 with BD) who had received carbamazepine for the treatment of a psychotic disorder. Two-thirds (22) of the BD patients and two of the 16 patients with other diagnoses appeared to respond to carbamazepine acutely. However, follow-up 3 to 4 years later revealed that only eight patients (seven with BD) were still receiving the drug. In only two cases was the treating psychiatrist convinced that carbamazepine was clearly beneficial. Side effects, particularly hematological abnormalities, during both short- and long-term treatment were troublesome. Carbamazepine may only infrequently be useful in the long-term care of patients who fail to respond to standard treatment.