Clozapine and chemotherapy: a dangerous couple or a necessary partnership?

• Published in: Drug and therapeutics bulletin Vol. 60; no. 2; pp. 29 - 31
• Main Authors: Campbell, Gillian, Wong, Eugene
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd 01.02.2022; BMJ Publishing Group LTD
• Subjects: Antipsychotic Agents - adverse effects; Antipsychotics; Case reports; Chemotherapy; Clozapine - adverse effects; Drug dosages; drugs: psychiatry; Granulocytes; Hematology; Humans; Lymphoma; Mental health; Mortality; Neutrophils; Patients; Pharmacy; Psychosis; Psychotropic drugs; Republished case report; Schizophrenia; Schizophrenia - drug therapy; United Kingdom > UK; Scotland; drugs: psychiatry; chemotherapy; schizophrenia
• ISSN: 0012-6543; 1755-5248
• DOI: 10.1136/dtb.2021.238377rep

Correspondence to Dr Gillian Campbell; gillian.campbell2@ggc.scot.nhs.uk SUMMARY A 48-year-old man with a history of schizophrenia was diagnosed with B-cell lymphoma of the small bowel. Background It is well recognised that adults with schizophrenia have significantly increased rates of mortality than the general population.1 Patients with schizophrenia are also recognised to have comparatively worse mortality rates if diagnosed with cancer.2 Clozapine is the most efficacious treatment available for treatment-resistant schizophrenia.3 National Institute for Health and Care Excellence guidelines advise that patients who have not responded to two antipsychotics (including one second-generation antipsychotic) should be offered clozapine,4 subject to monitoring given the risk of neutropaenia. Given the dramatic deterioration in his mental state on alternative antipsychotics after 4 months, the team decided to initiate a re-trial of clozapine, but with the addition of recombinant human granulocyte colony-stimulating factor (G-CSF) during days 5–10 of each cycle of R-CHOP, which is commonly used in R-CHOP-related neutropaenia. Others have also had success with using G-CSF in chemotherapy patients,8 including those with B-cell lymphoma.9 Grainger et al 10 conducted a literature review into similar cases and recommended that clozapine should be continued during chemotherapy for patients already established on clozapine treatment.