Pharmacopsychiatry 2024; 57(02): 92-93
DOI: 10.1055/s-0044-1779579
Abstracts │ XVth Symposium of the Task Force Therapeutic Drug Monitoring of the AGNP
Poster Abstracts

Elevation of alpha-1 acid glycoprotein during acute infection increases clozapine levels without signs of intoxication

Authors

  • M. Spangemacher

    1   Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
    2   Central Institute of Mental Health, Department of Psychiatry, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

  • X.M. Hart

    1   Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
    3   Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan

  • E. Saalfrank

    1   Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

  • G. Gründer

    1   Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

  • J. Reinwald

    1   Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
    2   Central Institute of Mental Health, Department of Psychiatry, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

  • A. Sartorius

    2   Central Institute of Mental Health, Department of Psychiatry, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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The monitoring of plasma levels of clozapine – one of the most effective antipsychotics – is highly recommended. Acute inflammatory processes can increase clozapine levels. Alpha-1 acid glycoprotein (AGP), an acute phase protein that significantly increases during inflammation, could also play a role in explaining the link between inflammation and clozapine concentration. This is the first case report that directly compares clozapine levels with AGP levels during an acute infection in a patient under continuous clozapine treatment.

A 58-year old male patient was treated with clozapine because of paranoid schizophrenia. The control laboratory examination detected a rise in clozapine levels up from 405 ng/ml to 1538 ng/ml under continuous treatment with 200 mg of clozapine per day. An influenza-A virus infection was detected by a smear test. AGP, Alpha-antitrypsin-1 (AAT) and C-reactive protein (CRP) were measured over the course of 14 days. An ANOVA was applied using CRP, AGP, and AAT as independent variables and clozapine concentration as dependent variables.

AAT, CRP, and AGP revealed a significant effect only for AGP upon clozapine levels, whereas CRP and AAT did not reach significance (p > 0.05). Post hoc regression demonstrated a significant association between AGP and clozapine concentration at p < 0.0001.

Clozapine has been reported to be predominantly bound to AGP, suggesting a causal relationship between elevated AGP and clozapine levels in our case. This could explain the absence of clozapine intoxication symptoms despite the total clozapine levels being as high as 1538 ng/mL.



Publication History

Article published online:
12 March 2024

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