Non-antibiotics reverse resistance of bacteria to antibiotics.

BACKGROUND: Most clinical isolates that exhibit a multi-drug resistant phenotype owe that resistance to over-expressed efflux pumps. Compounds that are efflux pump inhibitors (EPIs) reduce or reverse resistance to antibiotics to which the bacterial strain is initially resistant. We have evaluated non-antibiotics to reduce resistance of commonly encountered bacterial pathogens to antibiotics. MATERIALS AND METHODS: The effect of non-antibiotics on the susceptibility of bacteria to antibiotics was conducted by minimum inhibition concentration determinations of the antibiotic in the absence and presence of the non-antibiotic. RESULTS: Non-antibiotics such as chlorpromazine, amitryptiline and trans-chlorprothixene are shown to reduce or reverse resistance of a variety of bacteria to antibiotics. CONCLUSION: The results suggest that non-antibiotics may serve as adjuncts to conventional antibiotics for the therapy of problematic antibiotic infections caused by bacteria that owe their resistance to over-expressed efflux pumps.