TY - JOUR A1 - Liebchen, Uwe A1 - Weinelt, Ferdinand A1 - Scharf, Christina A1 - Schröder, Ines A1 - Paal, Michael A1 - Zoller, Michael A1 - Kloft, Charlotte A1 - Jung, Jette A1 - Michelet, Robin T1 - Combination of pharmacokinetic and pathogen susceptibility information to optimize meropenem treatment of Gram-negative infections in critically iII patients JF - Antimicrobial Agents and Chemotherapy N2 - Meropenem is one of the most frequently used antibiotics to treat life-threatening infections in critically ill patients. This study aimed to develop a meropenem dosing algorithm for the treatment of Gram-negative infections based on intensive care unit (ICU)-specific resistance data. Antimicrobial susceptibility testing of Gram-negative bacteria obtained from critically ill patients was carried out from 2016 to 2020 at a tertiary care hospital. Based on the observed MIC distribution, stochastic simulations (n = 1,000) of an evaluated pharmacokinetic meropenem model, and a defined pharmacokinetic/pharmacodynamic target (100%T->4xMIC while minimum concentrations were <44.5 mg/L), dosing recommendations for patients with varying renal function were derived. Pathogen-specific MIC distributions were used to calculate the cumulative fraction of response (CFR), and the overall MIC distribution was used to calculate the local pathogen-independent mean fraction of response (LPIFR) for the investigated dosing regimens. A CFR/LPIFR of >90% was considered adequate. The observed MIC distribution significantly differed from the EUCAST database. Based on the 6,520 MIC values included, a three-level dosing algorithm was developed. If the pathogen causing the infection is unknown (level 1), known (level 2), known to be neither Pseudomonas aeruginosa nor Acinetobacrer baumannii, or classified as susceptible (level 3), a continuous infusion of 1.5 g daily reached sufficient target attainment independent of renal function. In all other cases, dosing needs to be adjusted based on renal function. ICU-specific susceptibility data should be assessed regularly and integrated into dosing decisions. The presented workflow may serve as a blueprint for other antimicrobial settings. KW - meropenem KW - critically ill KW - antimicrobial susceptibility testing KW - Gram negative KW - dosing algorithm Y1 - 2022 U6 - https://doi.org/10.1128/aac.01831-21 SN - 0066-4804 SN - 1098-6596 VL - 66 IS - 2 PB - American Society for Microbiology CY - Washington ER -