title: Evaluation of the Safety of Clozapine Use in Patients With Benign Neutropenia.
abstract: OBJECTIVE
  To determine if clozapine can be safely utilized in psychiatric patients with benign neutropenia.
  
  
  METHODS
  A single-center, retrospective chart review study of records from 2001 to 2014 was conducted in an inpatient psychiatric hospital. Patients included had benign neutropenia prior to receiving clozapine and received clozapine using modified monitoring guidelines. All available laboratory values for absolute neutrophil count (ANC) before initiation and during treatment were evaluated. The primary endpoint was difference in ANC after initiation of clozapine from before clozapine.
  
  
  RESULTS
  A total of 26 patients were reviewed. The mean age at clozapine initiation was 34 years. The majority were African-American (73% [n = 19]), with more men than women (73% [n = 19] vs 27% [n = 7]). The mean lowest ANC value was not significantly different after clozapine initiation compared to before (1.5× 10³ cells/mm³ and 1.4 × 10³ cells/mm³, respectively; P = .22). The overall mean ANC was significantly higher after initiation than before (2.63 × 10³ cells/mm³ and 2.13 × 10³ cells/mm³, respectively; P < .001). There were no cases of severe neutropenia (ANC < 0.5 × 10³ cells/mm³), and no patient was discontinued for falling below modified guideline limits. There were fewer occurrences of mild neutropenia (ANC < 2.0 × 10³ cells/mm³) after clozapine initiation than before (16.0% and 31.4%, respectively; P < .001). There were also fewer occurrences of moderate neutropenia (ANC < 1.5 × 10³ cells/mm³), with 2.1% after clozapine and 13.3% before (P < .001).
  
  
  CONCLUSIONS
  Twenty-six patients with benign neutropenia were safely treated with clozapine. Pre-clozapine neutropenia did not predict increased risk for severe neutropenia with clozapine. Patients had significantly fewer episodes of mild and moderate neutropenia after receiving clozapine compared to before.
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, and Spring Grove Hospital Center, Baltimore, Maryland, USA.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Richardson
authors.affiliation: University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
authors.forename: Erica A
authors.initials: EA
authors.lastname: Davis
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, and Spring Grove Hospital Center, Baltimore, Maryland, USA.
authors.forename: Gopal R
authors.initials: GR
authors.lastname: Vyas
authors.affiliation: University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
authors.forename: Bethany A
authors.initials: BA
authors.lastname: DiPaula
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, and Spring Grove Hospital Center, Baltimore, Maryland, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: McMahon
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, Box 21247, Baltimore, MD 21228. dkelly@mprc.umaryland.edu.|Maryland Psychiatric Research Center, University of Maryland School of Medicine, and Spring Grove Hospital Center, Baltimore, Maryland, USA.
authors.forename: Deanna L
authors.initials: DL
authors.lastname: Kelly
mesh_terms: D000328:Adult; D002648:Child; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use*; D005260:Female; D019983:Guideline Adherence; D006778:Hospitals, Psychiatric; D006801:Humans; D007223:Infant; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced* / Q000175:diagnosis; D011618:Psychotic Disorders / Q000188:drug therapy*; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult
chemical_list: D003024:Clozapine