November 1984

HaloperidolPlasma Levels and Prolactin Response as Predictors of Clinical Improvement in Schizophrenia: Chemical v Radioreceptor Plasma Level Assays

Author Affiliations

From the Sections of Biological Psychiatry (Drs Smith, Baumgartner, Misra, DeJohn, and Mss Mauldin and Shvartsburd) and Neurochemistry and Neuropsychopharmacology (Dr Ho), Texas Research Institute of Mental Sciences; and the Departments of Psychiatry and Pharmacology, Baylor College of Medicine (Drs Smith and Misra), Houston. Dr DeJohn is now in private practice in Houston.

Arch Gen Psychiatry. 1984;41(11):1044-1049. doi:10.1001/archpsyc.1983.01790220034006

• The relationship between clinical response of schizophrenic patients to haloperidol and (1) blood levels of the medication, determined by both gas-liquid chromatography (GLC) and radioreceptor (RR) assays, or (2) prolactin response to the medication, was examined in an inpatient study using several fixed doses of haloperidol. Regression analysis disclosed a substantial curvilinear relationship between steadystate GLC-determined plasma haloperidol levels and decrease in Brief Psychiatric Rating Scale (BPRS) Psychosis factor scores; however, no substantial relationship was found between clinical response and RR plasma haloperidol levels or serum prolactin response to haloperidol. Our results suggest that steady-state plasma levels of haloperidol determined by the GLC chemical assay are a better predictor of decreases in BPRS Psychosis factor scores than RR assayed plasma haloperidol levels or prolactin response to haloperidol.