Neurotoxicity with combined use of lithium and thioridazine.

Four cases on a combination of lithium and thioridazine developed severe neurotoxic symptoms, e.g., delirium, seizures, encephalopathy and grossly abnormal EEG's. All patients had been on lithium without thioridazine prior to and after the neurotoxic episode with no complications or EEG changes. The possible risk of combining lithium and neuroleptics (thioridazine) is discussed and repeated EEGs are recommended as a preventive measure.