A retrospective study of 60 manic patients treated with neuroleptic
medications alone and 69 manic patients treated with a combination of
neuroleptic drugs and lithium revealed no difference between groups in side
effects and complications of treatment. Similarly, when comparisons were
made between patients treated with haloperidol only and those treated with
haloperidol and lithium, there were no differences in side effects and
complications. The results counter sporadic clinical reports suggesting a
toxic interaction between lithium and neuroleptic drugs.