Overview

• Researchers at the University of South Australia report in npj Antimicrobials and Resistance that common painkillers increased ciprofloxacin‑induced mutation rates in laboratory E. coli.
• Using the two painkillers together heightened mutation frequencies and drove high-level resistance to ciprofloxacin, with additional cross‑resistance to other antibiotic classes.
• Genetic data implicate overexpression of the AcrAB‑TolC efflux pump, and an efflux inhibitor partially or fully reversed resistance in some bacterial mutants.
• Nine non‑antibiotic medicines common in aged‑care settings were tested, with drugs such as diclofenac and furosemide also contributing to resistance development in some assays.
• Authors and coverage emphasize the results are in vitro and call for animal and clinical studies, advising awareness of polypharmacy rather than discontinuing over‑the‑counter painkillers.