Medicines are meant to heal, but some commonly used drugs may actually be putting people at greater risk. Research has now revealed that familiar over-the-counter painkillers like paracetamol and ibuprofen could be driving one of the world’s biggest health threats: antibiotic resistance.
A groundbreaking study from the University of South Australia, published in npj Antimicrobials and Resistance, found that these common painkillers not only promote antibiotic resistance when taken individually but also amplify it when used together.
How Painkillers Are Linked to Antibiotic Resistance
Researchers examined how non-antibiotic medications interact with the broad-spectrum antibiotic ciprofloxacin and the bacterium Escherichia coli (E. coli), a major cause of gut and urinary tract infections. They discovered that ibuprofen and paracetamol significantly increased bacterial mutations, making E. coli highly resistant to antibiotics.
As reported by TOI, this finding is particularly alarming for older adults in aged care facilities, where multiple medications are often prescribed simultaneously. According to the World Health Organization (WHO), antimicrobial resistance is a global public health threat that caused an estimated 1.27 million deaths in 2019 alone.
What Experts Are Saying
“Antibiotics have long been vital in treating infectious diseases, but their widespread overuse and misuse have fueled a global rise in antibiotic-resistant bacteria,” said Rietie Venter, lead researcher and Associate Professor at UniSA.
She explained that aged care facilities are especially vulnerable because residents often receive multiple drugs, including antibiotics, painkillers, and blood pressure medications. This combination creates an ideal environment for gut bacteria to adapt and resist antibiotics.
“In this study, we looked at the effect of non-antibiotic medicines and ciprofloxacin, commonly used for skin, gut, or urinary tract infections. When bacteria were exposed to ciprofloxacin with ibuprofen and paracetamol, they developed more genetic mutations than with the antibiotic alone. This helped them grow faster and become highly resistant. Worryingly, resistance extended beyond ciprofloxacin to several other antibiotic classes,” Prof. Venter said.
She further added, “We also uncovered the genetic mechanisms behind this resistance. Both ibuprofen and paracetamol activated bacterial defence systems that expel antibiotics, rendering them far less effective.”
The Study in Detail
The researchers tested nine medications commonly used in aged care settings. These included:
- Ibuprofen (anti-inflammatory pain relief)
- Diclofenac (anti-inflammatory for arthritis)
- Paracetamol/Acetaminophen (pain and fever relief)
- Furosemide (for high blood pressure)
- Metformin (for diabetes management)
- Atorvastatin (for lowering cholesterol)
- Tramadol (a strong post-surgical painkiller)
- Temazepam (for sleep disorders)
- Pseudoephedrine (a decongestant)
The study showed that antibiotic resistance is a much larger challenge than previously believed. It is no longer limited to the misuse of antibiotics alone but also influenced by interactions with other everyday medicines.
Implications for Healthcare
Prof. Venter emphasized the urgent need for awareness. “Antibiotic resistance isn’t just about antibiotics anymore. This study reminds us to carefully consider the risks of combining medications, especially in aged care where polypharmacy is common.”
She clarified that the findings do not mean people should stop using painkillers like ibuprofen or paracetamol. Instead, the focus should shift to understanding drug interactions and using medicines more mindfully.
“This doesn’t mean we should avoid these medications altogether,” she said. “But we must be far more conscious about how they interact with antibiotics, and that means looking beyond just two-drug combinations.”