You’ve probably reached for ibuprofen (Advil) or acetaminophen (Tylenol) countless times for headaches, fevers, or muscle aches—and felt perfectly safe doing so. But here’s the twist: new research suggests these go-to painkillers might be quietly helping antibiotic-resistant bacteria grow stronger. A fresh study (by the University of South Australia, published in npj Antimicrobials and Resistance) has revealed something pretty wild: when E. coli bacteria are exposed to the antibiotic ciprofloxacin alongside ibuprofen or acetaminophen, the bacteria mutate more—and become resistant not just to ciprofloxacin, but to a host of other antibiotics too. “We investigated whether nine commonly used NAMs in RACFs, including ibuprofen, diclofenac, acetaminophen, furosemide, metformin, atorvastatin, tramadol, temazepam, and pseudoephedrine at gut-relevant concentrations, enhance ciprofloxacin-induced mutagenesis in Escherichia coli. Our findings showed that ibuprofen and acetaminophen significantly increased mutation frequency and conferred high-level ciprofloxacin resistance,” the researchers have said.“Overall, our results demonstrated that two commonly consumed pain relief medications (ibuprofen and acetaminophen), can significantly enhance antibiotic resistance via mutation at gut-relevant concentrations in E. coli strain BW25113 and E. coli 6146. This was evident in the increased number of mutants and the enhancement of maximum cell density. Other NAMs, such as diclofenac and furosemide, also increased mutation frequency when compared to the non-NAM control (ciprofloxacin with DMSO). However, other NAMs such as temazepam, tramadol, and pseudoephedrine had minimal impact on the mutation frequency for E. coli BW25113 and E. coli 6146,” they added. The mechanism? These painkillers trigger bacterial defense systems—like turning on drug-efflux pumps (basically tiny sponges that suck in antibiotics and squeeze them right back out). That extra time gives bacteria the chance to mutate and evolve resistance.
Why does this matter more for the elderly?
Because polypharmacy (taking multiple medications) is incredibly common in residential care. Folks often take a cocktail of antibiotics, pain relief, meds for sleep, blood pressure, you name it. That’s the perfect storm to speed up antibiotic resistance.This isn’t just theory, antibiotic resistance is already killing people. According to the WHO, antibiotic-resistant infections were directly responsible for 1.27 million deaths in 2019 and contributed to nearly 5 million more overall.
Why painkillers matter more than you think
Really common drugs: Ibuprofen and acetaminophen are everywhere, your medicine cabinet, your local store, your go-to comfort tools.When combined with antibiotics: It’s this combo that really ratchets up the mutation rate in bacteria.
What should you do without panic?
First up—don’t panic or toss your painkillers. They’re generally safe and useful tools when used correctly.But:If you’re on antibiotics, talk to your healthcare provider before stacking in over-the-counter painkillers.For older loved ones or those in care homes, doctors might rethink how these drugs are combined.Be mindful of using multiple medications unnecessarily, that “just in case” pain reliever may not always be harmless.