Agranulocytosis: incidence and risk factors.
The use of clozapine has been limited by the risk of agranulocytosis. The cumulative incidence of agranulocytosis is 0.80% after 1 year and 0.91% after 1 1/2 years. Risk is greatest during the first 3 months of treatment and greater among women and the elderly. White-cell counts tend to spike upward before the occurrence of agranulocytosis. The occurrence of a white-cell count spike of > or = 15% above the previous count predicts development of agranulocytosis within 75 days (risk ratio = 3.02; 95% confidence interval, 1.38-6.57). Our results indicate that hematologic monitoring is necessary and effective. They also suggest that the frequency of monitoring could be reduced after the initial period of maximal risk.
Alvir
J M
JM
Hillside Hospital, Long Island Jewish Medical Center, Glen Oaks, N.Y. 11004.
Lieberman
J A
JA
D000328:Adult; D000367:Age Factors; D000380:Agranulocytosis / Q000139:chemically induced / Q000453:epidemiology*; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D015331:Cohort Studies; D016001:Confidence Intervals; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D015994:Incidence; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils; D011358:Product Surveillance, Postmarketing; D012307:Risk Factors; D012559:Schizophrenia / Q000188:drug therapy; D012737:Sex Factors; D014481:United States / Q000453:epidemiology
D003024:Clozapine