Quantitative efficacy of three antipsychotic drugs for schizophrenia based on a real-world study in China

Atypical antipsychotics exert remarkable long-term efficacy on the personal and social functions of schizophrenic patients. However, quantitative information on the social function of schizophrenic patients treated with atypical antipsychotics is scarce in the current clinical guidelines. In this study, we established pharmacodynamic models to quantify the time-efficacy relationship of three antipsychotic drugs based on the data from a real-world study conducted in China. A total of 373 schizophrenic patients who received antipsychotic monotherapy with olanzapine (n = 144), risperidone (n = 160), or aripiprazole (n = 69) were selected from a three-year prospective, multicenter study. The follow-up times were 13, 26, 52, 78, 104, 130, and 156 weeks after baseline. A time-efficacy model was developed with nonlinear mixed effect method based on changes in Personal and Social Performance (PSP) score compared with the baseline level. Crucial pharmacodynamic parameters, including maximum efficacy and drug onset time, were used to distinguish the efficacy of the three drugs. We quantified the time course of PSP improvement in patients after treatment with these three antipsychotics: olanzapine, risperidone, and aripiprazole reached an E_max value of 80.3%, 68.2%, and 23.9% at weeks 56.7, 29.2, and 36.8, respectively. General psychotic symptoms, onset frequency, and illness course were identified as significant factors affecting the efficacy of these drugs. The newly constructed models provide an evidence of the benefit of long-term maintenance therapy with atypical antipsychotics in individualized schizophrenia treatment in China.