Effect of lithium and neuroleptic combination on lithium transport, blood pressure, and weight in bipolar patients.

Patients treated with a combination of lithium (Li) and neuroleptics are reported to be at greater risk for toxicity. Previous findings suggested that treatment with a combination of Li and neuroleptics would increase the lithium ratio (LR) and intraerythrocyte Li levels. We studied 67 bipolar patients who were treated with Li alone (20 patients) or Li combined with haloperidol (17 patients), or Li combined with chlorpromazine (30 patients). Results revealed that the neuroleptic groups showed significantly lower LR and intracellular Li concentration as compared with those on Li alone. There was no significant difference in Li dosage among these three groups. No difference was found among these three groups with respect to mean blood pressure and weight. The number of hypertensive patients in the Li only group was twice as high as that in either of the two other groups, and the LR of the former was significantly higher than those of the latter groups.