Common Painkillers Like Ibuprofen, Paracetamol May Accelerate Antibiotic Resistance: Study Suggests - Video

New research published in npj antimicrobials and resistance journals reveals that commonly used over-the-counter drugs-ibuprofen and paracetamol-may be silently fueling one of the world's most pressing health crises: antibiotic resistance. The study, conducted by researchers at the University of South Australia, is the first of its kind to show that these medications, widely used for pain and fever, not only contribute to antibiotic resistance individually but may also amplify it when used together.

Antibiotic resistance is a growing global threat, with the World Health Organization warning of its significant impact on public health. The current study adds a new dimension to this challenge by demonstrating that non-antibiotic medications can influence bacterial behaviour and resistance patterns.

In their methodology, researchers assessed how Escherichia coli (E. coli)—a common bacterium responsible for gut and urinary tract infections—reacted when exposed to the broad-spectrum antibiotic ciprofloxacin alongside non-antibiotic medications such as ibuprofen and paracetamol. The results were alarming. The combination not only increased genetic mutations in E. coli but also made the bacteria highly resistant to ciprofloxacin and several other antibiotics across different classes.

“When bacteria were exposed to ciprofloxacin alongside ibuprofen and paracetamol, they developed more genetic mutations than with the antibiotic alone, helping them grow faster and become highly resistant,” said Associate Professor Rietie Venter, lead researcher of the study. “Worryingly, the bacteria were not only resistant to the antibiotic ciprofloxacin, but increased resistance was also observed to multiple other antibiotics from different classes.”

The research also identified that both ibuprofen and paracetamol activated bacterial defence mechanisms, enabling them to expel antibiotics and reduce their effectiveness. The study evaluated nine commonly prescribed drugs in aged care settings, including tramadol, diclofenac, metformin, and pseudoephedrine, raising concerns about the role of polypharmacy in elderly populations.

Researchers have called for further studies into long-term medication regimes to better understand how everyday medicines may be contributing to the growing threat of antibiotic resistance.

Reference: Chen, H., Sapula, S.A., Turnidge, J. et al. The effect of commonly used non-antibiotic medications on antimicrobial resistance development in Escherichia coli. npj Antimicrob Resist 3, 73 (2025). https://doi.org/10.1038/s44259-025-00144-w