Abstract
Objective
This systematic review aims to critically evaluate the link between antipsychotic drugs and bacterial infection risk, emphasising antimicrobial properties of antipsychotics, and microbiome changes that might heighten susceptibility to bacterial infections.
Methods
A systematic literature search was conducted across PubMed, Scopus, and Google Scholar, up to March 2024. Peer-reviewed articles that investigated the relationship between antipsychotics, their antimicrobial effects, microbiome alterations, and bacterial infection risk were included. Data extracted included antipsychotic type, infection risks, patient demographics, and study methodologies. Risk-of-bias assessments were performed using tools such as the Newcastle-Ottawa Scale and the SYRCLE risk-of-bias tool.
Results
The review analysed twenty-six studies detailing antimicrobial properties of antipsychotics, four studies on antipsychotic-induced microbiome alterations, and thirty-one studies assessing bacterial infection risk associated with antipsychotics. First-generation antipsychotics were observed to have broad antimicrobial properties, whereas second-generation antipsychotics primarily affected commensal bacteria. At least four antipsychotics were observed to disrupt the gut microbiota. A heightened risk of infection was observed among psychiatric cohorts as well as off-label antipsychotics use, with clozapine linked to a substantial increase in respiratory infection risk.
Discussion
Although antipsychotics remain indispensable in psychiatric care, their association with an increased risk of bacterial infections underscores the need for judicious prescribing and vigilant monitoring. The review identifies significant knowledge gaps attributable to inconsistent research methodologies, small study cohorts, lack of controls, and focus on a limited range of antipsychotics. Further standardised research is essential to deepen our understanding of these associations and to inform improved prescribing practices and risk mitigation strategies.
This systematic review aims to critically evaluate the link between antipsychotic drugs and bacterial infection risk, emphasising antimicrobial properties of antipsychotics, and microbiome changes that might heighten susceptibility to bacterial infections.
Methods
A systematic literature search was conducted across PubMed, Scopus, and Google Scholar, up to March 2024. Peer-reviewed articles that investigated the relationship between antipsychotics, their antimicrobial effects, microbiome alterations, and bacterial infection risk were included. Data extracted included antipsychotic type, infection risks, patient demographics, and study methodologies. Risk-of-bias assessments were performed using tools such as the Newcastle-Ottawa Scale and the SYRCLE risk-of-bias tool.
Results
The review analysed twenty-six studies detailing antimicrobial properties of antipsychotics, four studies on antipsychotic-induced microbiome alterations, and thirty-one studies assessing bacterial infection risk associated with antipsychotics. First-generation antipsychotics were observed to have broad antimicrobial properties, whereas second-generation antipsychotics primarily affected commensal bacteria. At least four antipsychotics were observed to disrupt the gut microbiota. A heightened risk of infection was observed among psychiatric cohorts as well as off-label antipsychotics use, with clozapine linked to a substantial increase in respiratory infection risk.
Discussion
Although antipsychotics remain indispensable in psychiatric care, their association with an increased risk of bacterial infections underscores the need for judicious prescribing and vigilant monitoring. The review identifies significant knowledge gaps attributable to inconsistent research methodologies, small study cohorts, lack of controls, and focus on a limited range of antipsychotics. Further standardised research is essential to deepen our understanding of these associations and to inform improved prescribing practices and risk mitigation strategies.
| Original language | English |
|---|---|
| Pages (from-to) | 171-183 |
| Number of pages | 13 |
| Journal | Journal of Psychiatric Research |
| Volume | 189 |
| Early online date | 24 May 2025 |
| DOIs | |
| Publication status | Published (in print/issue) - 30 Sept 2025 |
Bibliographical note
Publisher Copyright:© 2025 The Authors
Funding
This publication has emanated from research conducted with the financial support of Taighde \u00C9ireann \u2013 Research Ireland under Grant number GOIPG/2023/4515.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Francesca McDonagh reports financial support was provided by Irish Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
| Funders |
|---|
| Irish Research Council |
Keywords
- Antipsychotics
- bacterial infection
- respiratory infection
- microbiome
- antimicrobial resistance
- Bacterial infection
- Respiratory infection
- Antimicrobial resistance
- Microbiome
- Humans
- Mental Disorders/drug therapy
- Antipsychotic Agents/adverse effects
- Gastrointestinal Microbiome/drug effects
- Bacterial Infections/chemically induced
