JLE

Journal de Pharmacie Clinique

MENU

Clozapine and metabolites plasma levels in resistant schizophrenic patients Volume 18, issue 3, Septembre 1999

Figures

See all figures

Authors

Clozapine is an atypical antipsychotic drug. This molecule is metabolized in the liver and the two main metabolites are N-desmethyl clozapine and clozapine N-oxide. Clozapine is used in the treatment of resistant schizophrenic patients. Plasma concentrations of clozapine and its metabolites were measured in 27 patients with refractory schizophrenia, using high performance liquid chromatography. A correlation between dose and concentration was clearly shown in the results (r = 0,942 for clozapine), with an extensive inter-individual variation within the dose groups. There was a significant correlation between concentrations of clozapine and metabolites in plasma (r = 0,910 for N-desmethyl clozapine and r = 0,961 for clozapine N-oxide). There was also a correlation between concentrations of the two metabolites with a larger inter-patient variability (r = 0,742). Indices of N-desmethylation or N-oxidation were 0,75 ± 0,15 and 0,70 ± 0,16 respectively, without obvious dependance on the clozapine dose. Specificity of the method developed have improved therapeutic drug monitoring and gave rise to studies showing the variability of metabolism of clozapine in schizophrenic patients.