Plasma flupentixol concentrations and clinical response in acute schizophrenia.

Twenty-three acutely psychotic inpatients treated with flupentixol were included in the study. Steady-state plasma concentrations were compared with therapeutic outcome in a routine clinical setting. The threshold concentration for satisfactory antipsychotic effect appeared to be approximately 2 ng/ml. Controlled studies are needed to establish the existence and exact limits of a therapeutic window.