Systematic review of the effects of antimicrobial cycling on bacterial
resistance rates within hospital settings
Abstract
Aim Antimicrobial resistance is an evolving phenomenon with alarming
public health consequences. Antibiotic cycling is a widely known
antimicrobial stewardship initiative which encompasses periodical shifts
in empirical treatment protocols with the aim to limit selective
pressures on bacterial populations. Nonetheless, mathematical models
have challenged its presumable efficacy by favouring a higher
heterogeneity in antibiotic administration. We present a review of the
evidence regarding the actual impact of antimicrobial cycling on
bacterial resistance control within hospitals. Methods A systematic
literature review was conducted using the PubMed/MedLine, Embase, CINAHL
Plus and Global Health databases. Results A systematic search process
retrieved a sole randomised study, and so we broadened inclusion
criteria to encompass quasi-experimental designs. Fifteen studies formed
our dataset including seven prospective trials and eight
before-and-after studies. Nine studies evaluated cycling versus a
control group and produced conflicting results whilst three studies
compared cycling with antibiotic mixing, with none of the strategies
appearing superior. The rest evaluated resistance dynamics of each of
the on-cycle antibiotics with contradictory findings. Research protocols
differed in parameters such as the cycle length, the choice of
antibiotics, the opportunity to de-escalate to narrow-spectrum agents
and the measurement of indicators of collateral damage. This limited our
ability to evaluate the replicability of findings and the overall policy
effects. Conclusions Dearth of robust designs and standardised protocols
limits our ability to reach safe conclusions. Nonetheless, in view of
the available data we find no reason to believe that cycling should be
expected to improve antibiotic resistance rates within hospitals.