Common Painkillers and Antibiotic Resistance: A Growing Concern
Research from the University of South Australia suggests that widely used pain relievers like ibuprofen and acetaminophen could inadvertently be contributing to antibiotic resistance, which is a significant global health issue linked to millions of deaths each year.
Although ibuprofen and acetaminophen are popular choices for treating pain and fever, recent studies indicate they may play a role in exacerbating antibiotic resistance.
In an important investigation, scientists found that each drug could promote antibiotic resistance individually, and when taken together, they seem to amplify this effect.
By studying their interaction with the common antibiotic ciprofloxacin and the bacteria Escherichia coli, frequently responsible for gut and urinary tract infections, researchers noted that both ibuprofen and acetaminophen increased genetic mutations in the bacteria. This made them more resistant not only to ciprofloxacin but also to other antibiotics.
This discovery raises critical concerns, particularly for vulnerable populations, like older adults in care facilities where multiple medications are often prescribed. The findings emphasize the need for increased caution regarding routine drug use and its possible contribution to worsening antibiotic resistance.
The World Health Organization has marked antimicrobial resistance as a pressing global health concern, with bacterial resistance leading to an estimated 1.27 million deaths worldwide in 2019.
Ibuprofen and acetaminophen are among the most commonly used over-the-counter pain medications. Ibuprofen, known by brands like Advil and Motrin, is a nonsteroidal anti-inflammatory drug (NSAID) that alleviates pain, fever, and inflammation. Meanwhile, acetaminophen, often referred to as Tylenol, is typically used for pain and fever relief and lacks anti-inflammatory properties. Both are staples in most medicine cabinets and are frequently the go-to for headaches, colds, and everyday aches.
The Risks of Polypharmacy
Associate Professor Rietie Venter, the lead researcher, points out that these findings prompt significant questions about the dangers associated with polypharmacy in aged care.
“While antibiotics have been crucial in treating infections, their overuse and misuse have led to a rise in antibiotic-resistant bacteria globally,” says Assoc Prof Venter.
“This issue is particularly common in residential care facilities, where older individuals often receive prescriptions for various medications—not only antibiotics but also drugs for pain, sleep, or blood pressure—creating ideal conditions for gut bacteria to develop resistance to antibiotics.
“In our research, we explored the effects of non-antibiotic medications in conjunction with ciprofloxacin, an antibiotic for treating common infections. The bacteria exposed to both ciprofloxacin and these painkillers accumulated more genetic mutations compared to those treated with the antibiotic alone, resulting in faster growth and heightened resistance not only to ciprofloxacin but to multiple other antibiotics as well.
“We also identified the genetic mechanisms enabling this resistance, as both ibuprofen and acetaminophen stimulated the bacteria’s defenses to expel antibiotics, diminishing their effectiveness.”
Review of Common Medications
The study evaluated nine frequently prescribed medications in aged care settings: ibuprofen (for inflammation relief), diclofenac (for arthritis), acetaminophen, furosemide (for high blood pressure), metformin (for diabetes management), atorvastatin (to lower cholesterol), tramadol (stronger post-surgery pain relief), temazepam (for sleep disorders), and pseudoephedrine (for congestion).
Assoc Prof Venter asserts that the findings illustrate the complexities of antibiotic resistance, showing that common non-antibiotic medications might also contribute to the problem.
“Antibiotic resistance is no longer simply about antibiotics,” she states.
“This research serves as a poignant reminder that we must carefully evaluate the risks associated with taking multiple medications, especially in aged care, where residents often receive a mix of long-term treatments.
“This doesn’t imply that we should cease using these medications, but we definitely need to be more aware of how they interact with antibiotics, which includes considering more than just two-drug combinations.”
The researchers are advocating for further investigations into drug interactions among individuals on long-term treatment plans, aiming for a better understanding of how common medications could affect antibiotic effectiveness.
Reference: “The effect of commonly used non-antibiotic medications on antimicrobial resistance development in Escherichia coli” by Hanbiao Chen, Sylvia A. Sapula, John Turnidge, and Henrietta Venter, 25 August 2025, npj Antimicrobials and Resistance.
