Active monitoring of 12,760 clozapine recipients in the UK and Ireland. Beyond pharmacovigilance.
BACKGROUND
People prescribed clozapine for treatment-resistant schizophrenia have mandatory haematological monitoring through a case register for identifying reversible neutropenia.


OBJECTIVE
To quantify risk factors for agranulocytosis in subjects receiving clozapine.


METHODS
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.


RESULTS
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).


CONCLUSIONS
The case register yielded valuable information for guiding research into the causes of the haematological reactions.
Munro
J
J
Institute of Psychiatry, London.
O'Sullivan
D
D
Andrews
C
C
Arana
A
A
Mortimer
A
A
Kerwin
R
R
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000380:Agranulocytosis / Q000139:chemically induced* / Q000208:ethnology; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001208:Asia / Q000208:ethnology; D017691:Caribbean Region / Q000208:ethnology; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007494:Ireland; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced / Q000208:ethnology; D010349:Patient Compliance; D011358:Product Surveillance, Postmarketing; D012042:Registries; D012306:Risk; D012559:Schizophrenia / Q000188:drug therapy* / Q000208:ethnology; D013405:Suicide; D006113:United Kingdom
D014150:Antipsychotic Agents; D003024:Clozapine