RBC and plasma levels of haloperidol and clinical response in schizophrenia.

The authors conducted a fixed-dose study of haloperidol blood levels and clinical response in schizophrenic in patients and found that those with steady-state RBC haloperidol levels in the range of 2.4--5.4 ng/ml showed greater improvement than those with lower or higher levels. They found a similar , although nonsignificant, curvilinear relationship between plasma haloperidol levels and clinical response. These findings suggest that the relationship between haloperidol blood levels and clinical response fits a therapeutic window for the treatment of schizophrenia.