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Long-term pharmacokinetics of clozapine

Published online by Cambridge University Press:  03 January 2018

Martin Kurz*
Affiliation:
Department of Biological Psychiatry, Innsbruck University Clinics, Innsbruck, Austria
M. Hummer
Affiliation:
Department of Biological Psychiatry, Innsbruck University Clinics, Innsbruck, Austria
G. Kemmler
Affiliation:
Department of General Psychiatry, Innsbruck University Clinics, Innsbruck, Austria
I. Kurzthaler
Affiliation:
Department of Biological Psychiatry, Innsbruck University Clinics, Innsbruck, Austria
A. Saria
Affiliation:
Neurochemistry Unit, Innsbruck University Clinics, Innsbruck, Austria
W. W. Fleischhacker
Affiliation:
Department of Biological Psychiatry, Innsbruck, Austria
*
Martin Kurz, MD, Innsbruck University Clinics, Department of Biological Psychiatry, Anichstrasse 35, A-6020 Innsbruck, Austria. Tel: +43-512-504-3636; Fax: +43-512-504-3628

Abstract

Background

Previous studies of clozapine pharmacokinetics have shown a wide intra- and inter-individual variability of plasma levels in patients on stable clozapine doses. We investigated dose-plasma level relationships and intra-individual variability of plasma levels during maintenance treatment with clozapine.

Method

Forty-one patients on clozapine were followed for 26 weeks with repeated plasma level measurements and assessments of co-medication and clinical symptoms. In a second step, 15 patients on stable clozapine doses between treatment Weeks 12 and 52 were followed in the same way. Coefficient of variation was used as a parameter of plasma level deviation.

Results

Dose-plasma level correlations stayed significant from Week 6 to Week 26 (n=41). The group of patients followed up to Week 52 showed a mean intra-individual coefficient of variation of 52.8% (s.d. =20.6), and remained stable psychopathologically.

Conclusions

Even though clozapine plasma levels may show a significant degree of variation, this is not necessarily reflected in a change in psychopathology.

Type
Papers
Copyright
Copyright © 1998 The Royal College of Psychiatrists 

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