In this episode, I’ll discuss which antibiotic should be given first in sepsis – the beta-lactam or the vancomycin?
Quickly administering appropriate empiric antibiotic therapy is essential in the treatment of severe infections. If multiple antibiotics are required for empiric therapy to treat a severe infection (such as for empiric coverage of resistant gram-negative and gram-positive organisms), simultaneous administration can be appropriate. However, IV access, antibiotic compatibility, and other resources may require that antibiotic administration be sequential.
To determine whether the order of administration for beta-lactams and vancomycin had an impact on mortality when treating suspected bacteremia, researchers conducted a multicenter, observational study and recently published it in Clinical Infectious Diseases.
Data from over 3000 patients were analyzed. Beta-lactams were administered before vancomycin in a 4:1 ratio in the patient cohort.
The authors found that administration of a beta-lactam antibiotic prior to vancomycin protected against 7-day mortality with an adjusted odds ratio 0.48. Protection against 48 hour mortality also resulted in similar results with an adjusted odds ratio of 0.45.
As would be expected however, not all bacteremias were adequately covered by beta-lactams after culture and sensitivity data became available with almost 1 in 7 patients having a bacteremia caused by MRSA. Interestingly, when vancomycin was given before the beta-lactam to these patients with MRSA bacteremia, there was no statistically significant improvement in 48 hour or 7 day mortality rates.
The authors concluded:
For ill-appearing patients likely to be experiencing a BSI, prioritizing administration of a β-lactam over vancomycin may reduce early mortality, underscoring the significant impact of a relatively simple practice change on improving patient survival.
Although the study design can only suggest a correlation and not prove causation, if simultaneous administration is not an option, administering the beta-lactam first seems to be a rational approach.
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