Overview

• University of South Australia scientists exposed E. coli to nine widely used medicines alongside low-dose ciprofloxacin in culture.
• Ibuprofen or paracetamol increased bacterial mutation rates and yielded strains that continued growing despite ciprofloxacin.
• Genomic analysis tied the effect to mutations that upregulate efflux pumps, reducing antibiotic effectiveness across multiple drug classes.
• Combinations amplified resistance, including a 64-fold rise with ibuprofen plus diclofenac and 32-fold with ibuprofen plus paracetamol or metformin.
• The team warns about polypharmacy in settings such as care homes and calls for clinical research, with no changes to prescribing guidance reported.