Hematological adverse events in clozapine-treated children and adolescents

Ginny Gerbino-Rosen, David Roofeh, D. Andrew Tompkins, Doug Feryo, Laurie Nusser, Harvey Kranzler, Barbara Napolitano, Anne Frederickson, Inika Henderson, Joe Rhinewine, Sanjiv Kumra

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


Objective: To retrospectively examine rates of hematological adverse events (HAEs) in psychiatrically ill, hospitalized children treated with clozapine. Method: Clozapine treatment was administered in an open-label fashion using a flexible titration schedule, and data from weekly complete blood counts was obtained. The rate of neutropenia and agranulocytosis (HAEs) development was determined for 172 eligible patients (mean age at clozapine initiation, 15.03 ± 2.13 years) with a median observation period of 8 months. Results: Neutropenia (absolute neutrophil count <1,500/mm3) developed in 23 (13%) patients and agranulocytosis (absolute neutrophil count <500/mm 3) in one (0.6%) patient. The cumulative probability of developing an initial HAE at 1 year of clozapine treatment was 16.1% (95% confidence interval 9.7%-22.5%). Eleven (48%) of 24 patients who developed an HAE were successfully rechallenged on clozapine. Eight (5%) of 172 patients from this sample eventually discontinued clozapine because of an HAE (one agranulocytosis, seven neutropenia). Conclusions: The occurrence of HAEs is a significant risk associated with the administration of clozapine. However, in this sample, few children actually discontinued therapy because of an HAE and the incidence of agranulocytosis does not appear higher than what has been reported in the adult literature.

Original languageEnglish (US)
Pages (from-to)1024-1031
Number of pages8
JournalJournal of the American Academy of Child and Adolescent Psychiatry
Issue number10
StatePublished - Oct 2005
Externally publishedYes

Bibliographical note

Funding Information:
Disclosure: Dr. Kumra receives industry research funding from Pfizer and Janssen Pharmaceuticals and is on the speaker's bureau for Janssen Inc. The other authors have no financial relationships to disclose.

Funding Information:
Supported by NIMH grants MH-60221 and MH-64556 and a NARSAD award to Dr. Kumra; NSLIJ Research Institute General Clinical Research Center grant M01 RR018535 .


  • Agranulocytosis
  • Clozapine
  • Neutropenia


Dive into the research topics of 'Hematological adverse events in clozapine-treated children and adolescents'. Together they form a unique fingerprint.

Cite this