Olanzapine-induced and Risperidone-induced Leukopenia: A Case of Synergistic Adverse Reaction?

J Psychiatr Pract. 2018 Mar;24(2):121-124. doi: 10.1097/PRA.0000000000000292.


Leukopenia is a known hematological side effect of atypical antipsychotics. We report a case of an antipsychotic-naive patient with schizophrenia who developed leukopenia after a single dose of olanzapine, which worsened during subsequent treatment with risperidone. Normalization of the white blood cell counts occurred within 24 hours of risperidone discontinuation. Possible synergistic mechanisms underlying olanzapine-induced and risperidone-induced leukopenia are discussed. This case highlights the challenges in identifying and managing nonclozapine antipsychotic-induced leukopenia in a susceptible patient.

Publication types

  • Case Reports

MeSH terms

  • Antipsychotic Agents / administration & dosage
  • Antipsychotic Agents / adverse effects*
  • Drug Synergism
  • Female
  • Humans
  • Leukopenia / chemically induced*
  • Middle Aged
  • Olanzapine / administration & dosage
  • Olanzapine / adverse effects*
  • Risperidone / administration & dosage
  • Risperidone / adverse effects*
  • Schizophrenia / drug therapy*


  • Antipsychotic Agents
  • Risperidone
  • Olanzapine