Double‐Duty Drugs: Repositioning Antipsychotics to Combat Bacterial Infections

ABSTRACT Introduction This article provides a comprehensive review of the antibacterial properties of antipsychotics, exploring proposed pathways and mechanisms of action. While experimental evidence supports certain mechanisms, such as efflux pump inhibition, others, including the impact on the respiratory chain in M. tuberculosis and cell wall inhibition, remain insufficiently substantiated. Methods Current research primarily relies on in vitro experiments, with limited exploration of in vivo effects. The influence of antipsychotics on gut microbiota poses a significant concern, as alterations may lead to dysbiosis, which has been linked to various illnesses. Additionally, antimicrobial drugs can exert selective pressure, fostering resistance in bacterial strains. Results Repositioning antipsychotics as antimicrobials is further complicated by the need for higher doses than those approved for therapeutic use in humans, raising safety concerns. The use of antipsychotics in non‐psychotic populations is particularly problematic due to a lack of proven efficacy and potential adverse effects, such as metabolic disturbances, movement disorders, and sleep issues. Conclusions These challenges highlight the need for extensive in vivo and clinical studies to evaluate the antibacterial potential of antipsychotics, ensuring safety and efficacy. Careful monitoring and a balanced risk–benefit analysis are essential when considering antipsychotics for antimicrobial purposes.