Impact of β-lactam antibiotic therapeutic drug monitoring on dose adjustments in critically ill patients undergoing continuous renal replacement therapy

The objective of this study was to describe the effect of therapeutic drug monitoring (TDM) and dose adjustments of beta-lactam antibiotics administered to critically ill patients undergoing continuous renal replacement therapy (CRRT) in a 30-bed tertiary intensive care unit (ICU). beta-Lactam TDM data in our tertiary referral ICU were retrospectively reviewed. Clinical, demographic and dosing data were collected for patients administered beta-lactam antibiotics while undergoing CRRT. The target trough concentration range was 1-10x the minimum inhibitory concentration (MIC). A total of 111 TDM samples from 76 patients (46 male) with a mean +/- standard deviation age of 56.6 +/- 15.9 years and weight of 89.1 +/- 25.8 kg were identified. The duration of antibiotic therapy was between 2 days and 42 days. TDM identified a need for dose modification of beta-lactam antibiotics in 39 (35%) instances; in 27 (24%) samples, TDM values resulted in decreasing the prescribed dose of beta-lactam antibiotic whereas an increase in the prescribed dose occurred in 12 (11%) cases. In patients treated for hospital-acquired pneumonia and primary or secondary bacteraemia, the dosewas required to be decreased in 10/25 (40%) and 7/46 (15%) cases, respectively, to attain target concentrations. beta-Lactam TDM is a useful tool for guiding drug dosing in complex patients such as those receiving CRRT. Although over one-third of patients manifested concentrations outside the therapeutic range, most of these CRRT patients had excessive beta-lactam concentrations. (C) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.