Therapeutic drug monitoring of clozapine and norclozapine in schizophrenia

Abstract

The paper discusses are data of the therapeutic drug monitoring of clozapine received from 37 patients (98 samples in the whole), with various forms of schizophrenia undergoing treatment
in the conditions of a hospital. The nature of dependence between concentration of clozapine, its metabolite of a norclozapine and a drug dose is established.
Materials and methods. The method of a high performance liquid chromatography with massPspectrometric detection was developed for quantitative determination of clozapine and
norclozapine in the blood. Monitoring with the subsequent analysis of data was accompanied with necessary clinical information, in the form of special forms of inquiry – the monitoring cards.
Results and discussion: The obtained data of clozapine level were distributed in the following way: 16 % were in the therapeutic, 51 % in subPtherapeutic (< 350 ng/mL) and 29 %
conditionally toxic range (> 600 ng/mL), cases of alleged noncompliance did not exceed 3 %, in the appointment of clozapine at doses of 25 to 350 mg per day. Average concentrations of
clozapine and norclozapine were higher in nonPsmoker than in smokers.
Сonclusion. Distribution on concentrations for clozapine and norсlozapine is substantially normal character, slightly offset towards larger values. Therapeutic drug monitoring is a necessary
tool for the individualization and personalization of pharmacotherapy in the treatment of schizophrenia.