Evidence map›Paper›PMID 36242537›Full record

SynthesisSchizophrenia bulletin2023

Clozapine Therapy and COVID-19: A Systematic Review of the Prevalence Rates, Health Outcomes, Hematological Markers, and Patient Perspectives.

Grace Giles, Sunny Varghese, Gordon Shymko, Thinh Nguyen, Flavie Waters

Open access · bronzeAbstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Schizophrenia bulletin, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed, 3 pooled it
3.3field-weighted citation impact, top 8% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

8 citing papers in PubMed, 3 syntheses or guidelines pooled it, 18 citations in OpenAlex.

  1. Vaccination and clozapine use: a systematic review and an analysis of the VAERS database.European archives of psychiatry and clinical neuroscience · 2025
    Pooled it
  2. Pooled it
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  8. Clinical impact of reducing the frequency of clozapine monitoring: controlled mirror-image cohort study.The British journal of psychiatry : the journal of mental science · 2023
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 2 institutions in 1 country.

Grace GilesSouth Metropolitan Health Service, Peel and Rockingham Kwinana (PaRK) Mental Health Service, Rockingham, Western Australia, 6168, Australia.ORCID 0000-0003-1472-5742
Sunny VargheseSouth Metropolitan Health Service, Peel and Rockingham Kwinana (PaRK) Mental Health Service, Rockingham, Western Australia, 6168, Australia.
Gordon ShymkoSouth Metropolitan Health Service, Peel and Rockingham Kwinana (PaRK) Mental Health Service, Rockingham, Western Australia, 6168, Australia.
Thinh NguyenSouth Metropolitan Health Service, Peel and Rockingham Kwinana (PaRK) Mental Health Service, Rockingham, Western Australia, 6168, Australia.
Flavie WatersDivision of Psychiatry, School of Medicine, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia, 6009, Australia.
North Metropolitan Health Service · AUThe University of Western Australia · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND/

objectivesThere have been concerns that clozapine treatment may undermine the capacity of the body to fight infection and increase the vulnerability to contracting COVID-19. This review of recent cohort studies investigated (1) whether people with a severe psychiatric disorder are at increased risk of COVID-19 and complications, (2) the immunological response of clozapine-users who contract COVID-19, and (3) patients' perspectives on COVID-19 and the pandemic response.

methodsA systematic search of EMBASE, Medline, Pubmed, and PsycINFO databases using PRISMA guidelines using "COVID-19", "clozapine", and "vaccination" terms.

results18 studies (out of 330 identified) met all criteria (N = 119 054 including 8045 on clozapine). There was no strong evidence that clozapine users may be at increased risk of contracting COVID-19 or developing complications after adjusting for medical comorbidities. Hematological studies showed temporary reductions in neutrophils in COVID-19-positive patients and vaccination suggesting a clozapine effect in defence against infection. Vaccination studies did not report major adverse effects. Increased plasma levels of clozapine and neutropenia however point to COVID-19-related interference of clozapine metabolism. Patient surveys reported limited impact on mental health and positive attitudes regarding pandemic response.

conclusionThis review did not find compelling evidence that the immune system of clozapine users put them at risk of COVID-19 and further complications. Evidence of drug-infection interactions however points to the importance of adhering to consensus guidelines about clozapine therapy during the pandemic. More evidence using longitudinal designs is required to examine the longer-term effects of COVID-19 and vaccination in this vulnerable population.

Indexed as

Antipsychotic AgentsClozapineCOVID-19Mental DisordersHumansOutcome Assessment, Health CarePrevalenceAntipsychotic AgentsClozapineclozapinecoronavirusCOVID-19schizophrenia

Identifiers

PMID36242537
PMCPMC9620749
OpenAlexW4306290556

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.