Ibuprofen and acetaminophen (also known as paracetamol) are some of the most common medications people take for pain or fever.
But a new study from the University of South Australia has found that these everyday drugs may be contributing to a major global health crisis: antibiotic resistance.
This study is the first to show that not only can ibuprofen and acetaminophen lead to antibiotic resistance on their own, but they may actually make things worse when taken together.
Researchers looked at how these drugs interact with ciprofloxacin—a widely used antibiotic—and a common bacteria called E. coli, which causes infections in the gut and urinary tract.
The findings were worrying. When E. coli was exposed to both the painkillers and ciprofloxacin, the bacteria developed more genetic mutations than when exposed to the antibiotic alone.
These mutations made the bacteria grow faster and become more resistant to ciprofloxacin and even to other types of antibiotics. In other words, common over-the-counter pain medications could make antibiotics less effective.
This is a big concern, especially for older adults in aged care homes who often take multiple medications for different health problems.
The World Health Organization (WHO) has warned that antibiotic resistance is one of the biggest threats to global health. In 2019 alone, antibiotic-resistant bacteria were directly responsible for 1.27 million deaths worldwide.
Associate Professor Rietie Venter, who led the study, says the results highlight the need to rethink how we use medications.
In aged care, for example, residents are often prescribed a mix of drugs—not just antibiotics, but also medications for pain, sleep problems, blood pressure, and other issues. This creates a perfect environment for bacteria in the gut to develop resistance.
The research team tested nine common medications used in aged care: ibuprofen, acetaminophen, diclofenac (for arthritis), furosemide (for high blood pressure), metformin (for diabetes), atorvastatin (to lower cholesterol), tramadol (for pain after surgery), temazepam (for sleep problems), and pseudoephedrine (for nasal congestion).
Of these, ibuprofen and acetaminophen were found to be the most problematic when combined with ciprofloxacin. The study revealed that these painkillers activated the bacteria’s defense systems, helping them get rid of the antibiotic and survive.
This discovery shows that antibiotic resistance is more complicated than we once thought. It’s not just about how antibiotics are used; other common medications can also play a role.
“We’re not saying people should stop taking painkillers,” says Assoc Prof Venter. “But we need to be more aware of how they might affect the way antibiotics work—especially when people are taking multiple medications for a long time.”
The researchers say more studies are needed to understand how other drug combinations may affect antibiotic effectiveness. This is especially important for people who take long-term medications, like those living in aged care homes.
The hope is that by learning more about how common drugs interact, doctors and healthcare workers can make better decisions about treatment plans—and help slow down the spread of antibiotic-resistant bacteria.
If you care about pain, please read studies about Chronic morphine use for cancer pain may increase bone loss and findings of Scientists find a new hope for chronic pain.
For more about pain, please read studies about What you need to know about diabetes and joint pain and findings of Understanding the connection between liver disease and joint pain.
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