A new study has revealed that everyday painkillers such as ibuprofen and paracetamol may be contributing to the rise of antibiotic-resistant bacteria, a development that experts say could reshape how we view drug safety.
Researchers from the University of South Australia (UniSA) tested nine widely used non-antibiotic medicines, including ibuprofen, paracetamol, diclofenac and metformin, to see how they interact with antibiotics inside the gut. Surprisingly, they found that some of these common drugs encouraged bacteria to mutate faster, making them harder to kill with antibiotics.
Painkillers linked to stronger superbugs
The study titled, 'The effect of commonly used non-antibiotic medications on antimicrobial resistance development in Escherichia coli', was published in the journal Antimicrobials and Resistance. It showed that when E. coli bacteria (Escherichia coli) were exposed to painkillers alongside ciprofloxacin (a broad-spectrum antibiotic that kills many types of bacteria effectively), they developed stronger resistance. What’s more worrying is that this resistance wasn’t limited to one antibiotic, but spread across different classes of antibiotics, creating a broader health risk.
“When bacteria were exposed to ciprofloxacin alongside ibuprofen and acetaminophen, they developed more genetic mutations than with the antibiotic alone, helping them grow faster and become highly resistant. Worryingly, the bacteria were not only resistant to the antibiotic ciprofloxacin, but increased resistance was also observed to multiple other antibiotics from different classes,” said Rietie Venter, lead researcher, associate professor at UniSA.
The researchers tested nine drugs frequently used in aged care homes:
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- Ibuprofen – an anti-inflammatory pain reliever
- Diclofenac – an anti-inflammatory commonly used for arthritis
- Paracetamol (Acetaminophen) – for pain and fever
- Tramadol – a stronger pain medication often given after surgery
- Atorvastatin – used to lower cholesterol and fats in the blood
- Metformin – prescribed for high blood sugar linked to diabetes
- Furosemide – a diuretic for high blood pressure
- Temazepam – for treating sleeping problems
- Pseudoephedrine – a decongestant used for blocked noses
Why this matters
Antimicrobial resistance (AMR) is one of the top global public health and development threats. It happens when bacteria change in a way that makes antibiotics work less well, or not at all.
According to the World Health Organisation (WHO), AMR was directly responsible for 1.27 million global deaths in 2019 and contributed to 4.95 million deaths.
Until now, most focus has been on the misuse or overuse of antibiotics. But these new findings show that non-antibiotic medicines, often taken without a second thought, may also play a hidden role.
Experts warn the impact could be greatest in older people, as they are usually prescribed multiple medications, including painkillers and antibiotics at the same time. This cocktail of drugs could create the perfect conditions for resistant bacteria to thrive.
Should you stop taking painkillers?
Experts stress that the findings don’t mean people should avoid using pain killers altogether. Instead, the message is one of caution. Patients and healthcare providers should be more mindful of how these drugs interact with antibiotics, especially during long treatment courses.
The study highlights the need for further research and better monitoring of drug interactions in hospitals and care homes. As the fight against antimicrobial resistance intensifies, scientists say a broader approach is needed- one that considers not just antibiotics but also the everyday medicines millions rely on. Also Read: Paracetamol, aspirin or ibuprofen? The right way to use common painkillers
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