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Active monitoring of 12760 clozapine recipients in the UK and Ireland: Beyond pharmacovigilance

  • Janet Munro (a1), Desmond O'Sullivan (a2), Christopher Andrews (a2), Alejandro Arana (a3), Ann Mortimer (a4) and Robert Kerwin (a1)...

People prescribed clozapine for treatment-resistant schizophrenia have mandatory haematological monitoring through a case register for identifying reversible neutropenia.


To quantify risk factors for agranulocytosis in subjects receiving clozapine.


Data from 12 760 subjects registered to receive clozapine from January 1990 to April 1997 were analysed. Risk factors for agranulocytosis were quantified using a Cox proportional-hazards regression analysis.


The risk for agranulocytosis in Asian subjects was 2.4 times that in Caucasians (P=0.03). There was an age-related increase in risk of 53% per decade (P=0.0001).


The case register yielded valuable information for guiding research into the causes of the haematological reactions.

Corresponding author
Dr R. Kerwin, Institute of Psychiatry, De Crespigny Park, London SE5 8AF
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Declaration of interest

The Clozaril Patient Monitoring Service is part of Novartis Pharmaceuticals. Three authors (D.O'S., C. A., A. A.) are employed by Novartis and three (J. M., A. M., R. K.) are in receipt of research grants from the company.

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  • ISSN: 0007-1250
  • EISSN: 1472-1465
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Active monitoring of 12760 clozapine recipients in the UK and Ireland: Beyond pharmacovigilance

  • Janet Munro (a1), Desmond O'Sullivan (a2), Christopher Andrews (a2), Alejandro Arana (a3), Ann Mortimer (a4) and Robert Kerwin (a1)...
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