Overview

• University of South Australia scientists found ibuprofen and paracetamol increased genetic mutations in E. coli exposed to ciprofloxacin, producing high-level resistance in vitro.
• The effect strengthened when the painkillers were used together, with bacteria also showing increased resistance to multiple other antibiotic classes.
• Genetic analyses indicated the drugs activated bacterial defense systems that expel antibiotics, reducing treatment effectiveness.
• The peer-reviewed work, published in npj Antimicrobials and Resistance, tested nine medicines common in aged care and reported up to a 12-fold rise in mutation-driven resistance in two E. coli strains.
• Independent experts noted the findings come from lab experiments only and urged animal or gut-model studies, while the authors advised against stopping painkillers and called for research on long-term drug interactions.