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Clozapine therapy tied to increased risk of COVID-19 infection

Key clinical point: Clozapine treatment is associated with an increased risk of COVID-19 infection compared with any other antipsychotic medication.

Major finding: Patients treated with clozapine were at an increased risk of COVID-19 infection compared with those treated with other antipsychotic medication (hazard ratio [HR], 2.62; 95% confidence interval [CI], 1.73-3.96). This association remained significant after adjustments (adjusted HR, 1.76; 95% CI, 1.14-2.72).

Study details: A retrospective study of 6,309 patients with schizophrenia-spectrum disorders (mean age, 46.5 ± 14.8 years; 61.7% men) treated with antipsychotics in London during the COVID-19 pandemic.

Disclosures: This work was supported by the Clinical Records Interactive Search system, funded and developed by the National Institute for Health Research Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, and a joint infrastructure grant from Guy’s and St Thomas’ Charity and the Maudsley Charity. Dr. Richard D. Hayes received research funding from Roche, Pfizer, Janssen, and Lundbeck; Dr. Daniela Fonseca de Freitas received research funding from Janssen and Lundbeck; and Dr. James H. MacCabe received research funding from Lundbeck.


“Clozapine, a 2nd generation antipsychotic drug, appears unique in its ability to help individuals with schizophrenia who have not achieved treatment response with other antipsychotic medication. However, clozapine is also associated with a range of significant potential adverse effects including weight gain, diabetes, pneumonia and possible compromise of immune functioning. This recent report found that receiving clozapine treatment is associated with increased risk of COVID-19 infection, compared with other antipsychotics that is attenuated but not completely explained by differences in sociodemographic factors such as age and ethnicity and clinical factors such as body mass index (BMI). The authors caution that this analysis is based on a relatively small number of cases, and has other methodological limitations. However, COVID-19 risk is an additional factor that clinicians may need to consider when electing to start clozapine therapy.”

Martha Sajatovic, MD

Professor of Psychiatry and of Neurology

Willard Brown Chair in Neurological Outcomes Research

Director, Neurological and Behavioral Outcomes Center, University Hospitals Cleveland Medical Center

Case Western Reserve University School of Medicine


Govind R et al. Br J Psychiatry. 2020 Jul 27. doi: 10.1192/bjp.2020.151.