Prolonged infusions of β-lactams are increasingly being utilized because of increased antimicrobial resistance and a lack of new antibiotics in the pipeline.
A retrospective, observational study evaluated adult patients who received at least 72 hours of piperacillin-tazobactam or meropenem in a medical and surgical intensive care unit (ICU) at an academic medical center. In the first 6 months of the study, all patients received conventional intermittent dosing; in the second 6 months, all patients received these antibiotics by prolonged infusions. The main outcome comparisons between groups were duration of ventilator support, duration of ICU and hospital length of stay, and in-hospital mortality.
A total of 121 patients were included: 54 patients in the intermittent (67% piperacillin-tazobactam, 33% meropenem) and 67 patients in the prolonged group (81% piperacillin-tazobactam, 19% meropenem). The prolonged group demonstrated a significant decrease in ventilator days (−7.2 days; 95% confidence interval [CI], −12.4 to −2.4), ICU length of stay (−4.5 days; 95% CI, −8.3 to −1.4), and hospital length of stay (−8.5 days; 95% CI, −18.7 to −1.2) compared with the intermittent group. The risk of in-hospital mortality was 12.4% in the prolonged infusion group and 20.7% in the intermittent infusion group corresponding to an odds ratio of 0.54 (0.18-1.66).
The results of this study show that the use of prolonged infusions of piperacillin-tazobactam and meropenem could potentially improve clinical outcomes in critically ill populations. As antibiotic resistance continues to increase in gram-negative pathogens, these β-lactam dosing strategies will be important for appropriate treatment.
Dow et al. retrospectively compared a prolonged infusion dosing strategy to a traditional intermittent dosing strategy for piperacillin/tazobactam and meropenem in a combined medical/surgical intensive care unit. All patients in the study received at least 72 hours of study antibiotics. The study showed significantly improved outcomes in reduced ventilator days and ICU and hospital length of stay, as well as a trend toward lower mortality with the prolonged infusion strategy.
From the *Department of Pharmacy, Froedtert & The Medical College of Wisconsin; †Pharmacy Practice Division, University of Wisconsin School of Pharmacy; ‡Department of Medicine-Infectious Diseases, University of Wisconsin Hospital and Clinics; §Social and Administrative Sciences Division, University of Wisconsin School of Pharmacy; and ∥Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, WI.
Correspondence to: Jeffrey T. Fish, PharmD, University of Wisconsin Hospital and Clinics, Pharmacy Services, 600 Highland Ave, F6/133-1530, Madison, WI 53792. E-mail: firstname.lastname@example.org.
This study has no sources of funding.
Presented in part at the Great Lakes Pharmacy Residency Conference, West Lafayette, IN, April 29-May 1, 2009.
Dr Fox was previously on the speaker's bureaus of Wyeth (which makes piperacillin-tazobactam) and Cubist (which markets meropenem). Dr Rose has received research funding and is on the speaker's bureau for Cubist. All other authors have no competing interests to disclose.