title: Filgrastim treatment of three patients with clozapine-induced agranulocytosis.
abstract: BACKGROUND
  Agranulocytosis is the most serious side effect of clozapine therapy, occurring in approximately 1% of all treated patients. Despite careful blood monitoring, a significant number of cases of agranulocytosis and resulting fatalities have occurred. Strategies are needed to manage clozapine-induced agranulocytosis more safely.
  
  
  METHODS
  This report describes the management of three state hospital inpatients who developed clozapine-induced agranulocytosis. All patients were diagnosed as having chronic paranoid schizophrenia according to DSM-III-R criteria and had previously failed to respond to treatment with standard antipsychotic medications. After onset of agranulocytosis, all patients were transferred to a medical service in a university hospital and treated with recombinant granulocyte colony-stimulating factor (filgrastim).
  
  
  RESULTS
  White blood count and absolute neutrophil count returned to within normal limits in each patient after 5 to 8 days of treatment with filgrastim 300 micrograms/day subcutaneously. No side effects were observed during filgrastim treatment.
  
  
  CONCLUSIONS
  Treatment with filgrastim appears to be safe and effective in decreasing the duration of clozapine-induced agranulocytosis. While further studies are necessary to establish the safety and effectiveness of this treatment, filgrastim should presently be considered a treatment of choice for clozapine-induced agranulocytosis.
authors.affiliation: Department of Psychiatry, University of Rochester Medical Center, N.Y., USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Lamberti
authors.forename: T J
authors.initials: TJ
authors.lastname: Bellnier
authors.forename: S B
authors.initials: SB
authors.lastname: Schwarzkopf
authors.forename: E
authors.initials: E
authors.lastname: Schneider
mesh_terms: D000328:Adult; D000380:Agranulocytosis / Q000097:blood / Q000139:chemically induced* / Q000188:drug therapy*; D002908:Chronic Disease; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils; D011994:Recombinant Proteins / Q000627:therapeutic use; D012563:Schizophrenia, Paranoid / Q000188:drug therapy / Q000523:psychology; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D003024:Clozapine; D000069585:Filgrastim