Surprising Discovery Reveals That Common Painkiller Paracetamol Also Acts as a Potent Antimicrobial Agent
Nikhil Prasad Fact checked by:Thailand Medical News Team Apr 11, 2025 1 day, 19 hours, 21 minutes ago
Medical News: A Surprising Role for Paracetamol Beyond Pain and Fever Relief
Paracetamol, also known as acetaminophen, is among the most widely used over-the-counter medications in the world. It's a household name in virtually every country, frequently taken for headaches, fever, and minor aches. But now, a groundbreaking review conducted by an international team of researchers from Gopalganj Science and Technology University and BioLuster Research Center Ltd. in Bangladesh, the University of Dhaka in Bangladesh, and the Federal University of Paraíba and Regional University of Cariri in Brazil, has shed light on an entirely unexpected property of this common drug—its antimicrobial capabilities.
Surprising Discovery Reveals That Common Painkiller Paracetamol Also Acts as a Potent Antimicrobial Agent
This
Medical News report reveals that far from being a simple fever reducer, paracetamol actually has broad-spectrum antimicrobial effects. The study reassessed decades of scientific data and database reports and found compelling evidence that paracetamol and its derivatives can inhibit the growth of a wide range of bacteria, fungi, viruses, and protozoa. But this revelation is a double-edged sword—because while it opens up exciting potential for antimicrobial applications, it also raises serious concerns about rising microbial resistance and potential toxicity.
Evidence from 40 Years of Scientific Reports
The research team analyzed over 4.5 million published entries and shortlisted 163 qualified studies from 1984 to 2024. Of these, 76 directly addressed paracetamol’s antimicrobial activity, spanning bacterial (14), viral (44), fungal (10), and protozoal (8) studies. The findings show that not only does paracetamol affect gram-positive and gram-negative bacteria, but its metabolites and derivatives also demonstrate powerful activity against fungal and viral pathogens. For example, PMCL derivatives were found effective against Staphylococcus aureus, Escherichia coli, Candida albicans, Aspergillus niger, and even against Mycobacterium tuberculosis. Moreover, its metabolite NAPQI also exhibited antimicrobial activity. The study found that even paracetamol-caffeine combinations and various metal-complexed forms enhance these antimicrobial effects. Notably, paracetamol was active against over 117 microbial strains, including drug-resistant varieties.
Viral and Fungal Threats Also in Paracetamol's Crosshairs
Paracetamol’s antiviral effects were found to be particularly intriguing. Its metabolite AM404 inhibits replication of the dengue virus by targeting viral protein NS4B. PMCL also suppressed symptoms of respiratory infections and improved lung function in animal studies infected with influenza A. It showed promise in managing viral symptoms in both children and adults, even being used safely during COVID-19.
Fungal pathogens like Candida albicans, Aspergillus flavus, and Penicillium chrysogenum were also suppressed by various PMCL-derived compounds. Some formulations exhibited inhibition zones as wi
de as 28mm—a clear indication of potent antifungal effects.
The Double-Edged Sword of Resistance and Toxicity
Despite these promising effects, the widespread and often uncontrolled use of paracetamol may contribute to a new kind of health crisis—antimicrobial resistance. The study explains that microbes develop resistance by limiting drug entry, deploying efflux pumps, modifying drug targets, or activating alternative metabolic pathways. Paracetamol may unintentionally support some of these resistance mechanisms when overused or misused.
In fact, studies found that chronic use of paracetamol could accelerate the spread of resistant genes in E. coli and other bacteria. In one instance, it was shown to enhance biofilm formation in Staphylococcus aureus, thereby strengthening its defense against antibiotics.
Danger to Organs and the Microbiome
Beyond resistance, paracetamol’s toxicity—especially to the liver and kidneys—is well documented. At high doses or with chronic use, the body converts paracetamol into toxic compounds like NAPQI, which can cause acute liver failure and even death. The drug’s effects on the gut microbiome were also concerning. Researchers noted that paracetamol's antimicrobial action may disturb the gut’s delicate microbial balance, potentially leading to conditions like inflammatory bowel disease or even immune dysfunction.
Moreover, combinations like paracetamol with caffeine—which are popular in many countries—pose further health complications. Though caffeine may improve absorption or clearance in some cases, excessive intake risks miscarriage, fetal growth issues, or cardiac irregularities, especially in pregnant women and children.
Can Paracetamol Be a Future Antimicrobial Agent
The review also explored whether paracetamol or its modified forms could be developed as standalone antimicrobials or adjunct therapies. Researchers highlighted PMCL’s potential anti-quorum sensing (QS) activity—disrupting bacterial communication that governs toxin release and biofilm formation. These anti-QS properties could be useful in future drug combinations to enhance treatment efficacy while reducing resistance.
However, the authors caution that more rigorous studies are required before paracetamol can be safely repurposed. For now, they strongly advise against using it as an antimicrobial without medical supervision.
Final Thoughts and Conclusion
The study’s revelations have triggered a call for greater public awareness and stricter regulation of paracetamol use. This seemingly benign drug, taken so casually across the globe, is far more complex and potentially dangerous than once believed. While its antimicrobial potential could be harnessed in the future, irresponsible usage could fuel the next wave of drug-resistant infections.
Healthcare providers and pharmacists must recognize paracetamol’s dual nature—not just as an analgesic but as a pharmacological agent capable of altering the body’s microbial environment and immune responses. Striking the right balance between benefit and harm is crucial. Until then, paracetamol should be used with caution, especially in combination therapies or in individuals with preexisting liver or immune issues.
The study findings were published in the peer reviewed journal: Pharmaceutical Science Advances.
https://www.sciencedirect.com/science/article/pii/S277321692500008X
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