Taking two common painkillers may be raising your risk of suffering from a deadly bacterial infection, a study suggests.

Ibuprofen, known as Advil, and acetaminophen, known as Tylenol, are common over-the-counter medications taken by millions annually for alleviating headaches, back and neck pain, fevers, and other conditions.

However, Australian researchers caution that these inexpensive drugs, available for about 20 cents per pill, might enhance antibiotic resistance, complicating the treatment of dangerous bacterial infections.

Through laboratory experiments, they discovered that these pain relievers increased the resistance of bacteria to a commonly used antibiotic, whether used individually or in combination.

The study was carried out in the lab, and not in humans, meaning the results may not fully translate to the real-world.

The researchers emphasized that this study serves as a caveat against frequent use of painkillers, especially for those in care facilities who often take them alongside antibiotics and face a higher risk of bacterial infections.

Globally, around 1.27 million people succumb to antibiotic resistance each year, a situation the CDC describes as ‘one of the greatest public health challenges of our time’.

Dr Rietie Venter, a microbial resistance researcher who led the study, said: ‘Antibiotic resistance isn’t just about antibiotics anymore.

Experts noted that consuming Advil and Tylenol, well-known OTC painkillers, might increase your risk of developing an antibiotic-resistant infection (stock photo).

‘This study is a clear reminder that we need to carefully consider the risks of using multiple medications, particularly in aged care where residents are often prescribed a mix of long-term treatments.’

She added: ‘This doesn’t mean we should stop using these medications, but we do need to be more mindful about how they interact with antibiotics, and that includes looking beyond just two-drug combinations.’

In the study, researchers tested acetaminophen, commonly used to relieve fevers, and ibuprofen, commonly found in flu medications. 

Other drugs tested in the study included diclofenac, an arthritis treatment, furosemid, to treat high blood pressure, metformin, to control high blood sugar, atorvastatin, to reduce cholesterol, tramadol, a strong painkiller, temazepam, used to treat sleep problems, and pseudoephedrine, a decongestant.

These drugs contain different active ingredients and do not contain acetaminophen or ibuprofen.

The scientists placed the drugs in a petri dish alongside varying concentrations of the antibiotic ciprofloxacin, the first-line of defense against bacterial infections. 

The bacteria E.coli, commonly found in human intestines and often behind recalls of contaminated food, was added and the dishes were heated for 20 hours to 98.6 degrees Fahrenheit (37 degrees Celsius), to mirror the temperature in the human body.

Results showed that when bacteria were exposed to ciprofloxacin alongside acetaminophen and ibuprofen, the bacteria developed more mutations than when just exposed to ciprofloxacin. 

This helped the bacteria grow faster and become highly resistant to the antibiotic, as well as to multiple antibiotics from different classes.  

In the lab tests, the scientists used E.coli, a common bacteria often found in the human gastrointestinal tract (stock photo)

About 9.9million people are prescribed ibuprofen in the US every year, estimates suggest, with millions of others taking the drug over the counter.

An estimated 52million people take acetaminophen in the US every year.

The CDC said there are about 2.8million antibiotic resistant infections in the US every year.

More than 35,000 people also die from these infections annually, according to estimates.

The World Health Organization had previously warned that antibiotic resistance ‘threatens the effective prevention and treatment of an ever-increasing range of infections’ and that it is ‘an urgent public health threat’.

Infections that are resistant to these drugs are often referred to as ‘super infections’.

The study was revealed in the journal Nature: Antimicrobials and Resistance.