New Problems With Ibuprofen and Acetaminophen Revealed

A new study from Nature shows that both painkillers, especially when used together, can contribute to antibiotic resistance in the setting of a bacterial infection. So they may be helping an acute fever but potentially make infection worse in the future. The finding comes amid decreasing options we have to treat antibiotic-resistant organisms globally.

A recent study from August 2025 in Nature looked at nine different medications: acetaminophen, ibuprofen, diclofenac, furosemide, atorvastatin, metformin, pseudoephedrine, temazepam, and tramadol. In the presence of ciprofloxacin, a commonly used antibiotic, ibuprofen and acetaminophen increased the mutation rates of E. coli, a common human bacterial strain. Two different strains of E. coli showed increased mutations and resistance to ciprofloxacin in the presence of these medications. This happens because one of the mechanisms a bacterial cell uses to rid itself of a toxin (the antibiotic in this case) becomes altered in the presence of these medications. It is called an efflux pump