• A blind controlled study evaluated the prediction of response to chlorpromazine treatment in 37 schizophrenics on the basis of actual outcomes. Prior to the initiation of treatment, blood samples were taken three hours after a dose of 50 mg of chlorpromazine for the analyses of the drug and its metabolites. The chlorpromazine therapy was then begun and continued for three months. The results agreed with our previous conclusion that patients who showed high levels of the metabolites after a single dose of chlorpromazine tended to have poor clinical improvement with chlorpromazine and that the responders showed the opposite pattern. The predictability of response to chlorpromazine therapy is significantly high in the patients with very low or high levels of the metabolites. However, this is useful at best in 46% of the subjects studied.
Sakurai Y, Takahashi R, Nakahara T, Ikenaga H. Prediction of Response to and Actual Outcome of Chlorpromazine Treatment in Schizophrenic Patients. Arch Gen Psychiatry. 1980;37(9):1057-1062. doi:10.1001/archpsyc.1980.01780220095011