Cycling of antibiotics in hospitals is unlikely to prevent resistance
The practice of alternating between different classes of antibiotic agents in hospitals is unlikely to reduce the spread of resistance, according to the authors of a new study.
The strategy, known as cycling, has been proposed as a way of tackling
resistance — once bacteria start to develop resistance to one drug
a change in antibiotic class would render them susceptible to treatment
again. The authors show, using mathematical models of how microbial infections
spread within hospitals and how microbes build resistance to antibiotics,
that the mechanism by which this strategy would work is untenable. Instead,
they suggest that mixing drugs — where each patient receives one
of several classes of antibiotics used simultaneously in the hospital — would
be more effective.
Hayley Wickens, microbiology pharmacist at St Mary’s Hospital,
London, commented: “Modelling exercises such as this one lend weight
to the theory that heterogeneous antimicrobial prescribing, rather than
strict adherence to a cycling regimen, is likely to minimise emergence
of resistance.”
She added that many of the “real patient” trials in this
area have been conducted in the US and that there is a need for well-designed
clinical studies in the UK. “There is an increasing number of pharmacists
specialising in this area and they are ideally placed to be involved
in such studies, especially as expert input from antimicrobial teams
including pharmacists has been shown to have an impact on reducing inappropriate
antimicrobial prescriptions,” she said. The study is published
in the Online Early Edition of Proceedings of the National Academy
of Sciences |
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