Carbapenem de-escalation as an antimicrobial stewardship strategy: a narrative review

Increased carbapenem prescribing has contributed to rising rates of carbapenem-resistant bacterial pathogens. Although antimicrobial stewardship efforts that facilitate de-escalation of carbapenems to alternative agents can minimize unnecessary exposure, clinicians may be hesitant to de-escalate therapy due to concerns for potentially compromising patient outcomes. A literature search was performed to characterize carbapenem de-escalation strategies and assess associated patient outcomes. A total of 228 articles were screened on PubMed, and 15 studies that examine the de-escalation of carbapenems to non-carbapenem alternatives were identified for inclusion. The studies primarily included non-critically ill and immunocompetent adults involving over 5000 patients receiving carbapenem therapy for a variety of infections, most commonly urinary tract infections, pneumonia, and skin and soft tissue infections. Twelve of 15 studies reported carbapenem de-escalation as part of their antimicrobial stewardship programme (ASP) initiatives. Overall, carbapenem de-escalation led to a reduction in carbapenem use by 2 to 5 days and was not associated with negative outcomes (higher rates of clinical failure or mortality) compared with the continuation groups. Baseline characteristics of patient age, comorbidities, severity of illness, infection site and pathogen were not consistently described or balanced between groups, which may bias results in favour of de-escalation. Identification of which patients to consider for antibiotic de-escalation is nuanced and requires careful consideration of complex patient history, infection type, clinical stability and microbiology results. Although findings support carbapenem de-escalation as a promising ASP strategy, more high-quality studies are needed to more definitely elucidate the impact of carbapenem de-escalation on clinical outcomes.