A study of the stability of plasma clozapine concentration in patents taking clozapine chronically

Objective:To study the stability of plasma clozapine concentration in patients taking clozapine chronically and the related factors.Method:Plasma clozapine concentration was measured three times in 305 inpatients with schizophrenia who had taken clozapine for more than one year.Results:There was a fluctuation in level of plasma clozapine between the three times,that is,210 cases more than 20.0%,among them 127 cases more than 25.0%,50 cases more than 50.0%,7 cases more than 100.0%,among them 1 case more than 404.2%.The stability of plasma clozapine concentration was correlated to gander,smoking,combined drugs taking and dosage of clozapine and so forth.Conclusion:Plasma clozapine concentration of those patients who had taken clozapine chronically may change by gander,smoking,combined drugs taking and dosage of clozapine.