Therapeutic Drug Monitoring of Beta-Lactam Antibiotics in Burns Patients—A One-Year Prospective Study

Abstract

Background: Beta-lactams are first-line antibiotics for the management of superficial infections due to burn injury. There is sparse data available on therapeutic drug monitoring (TDM) in patients with burns in a ward setting. This study was conducted to evaluate the utility of a beta-lactam TDM program in a cohort of burn injury patients in a ward environment. Methods: Steady-state blood samples were collected immediately before a scheduled dose. The therapeutic concentration targets assessed were (1) free antibiotic concentrations exceeding the minimum inhibitory concentration (MIC; fT > MIC) and (2) free concentrations =4נMIC of the known or suspected pathogen (fT > 4נMIC). The duration of therapy was also assessed. Results: A total of 50 patients were included for TDM over a 12-month period. The mean (ᓄ) age was 49 ᠱ6 years. The mean percent total body surface area burn was 17 ᠱ3%. The mean serum creatinine concentration was 86 ᠲ0 孯le/L. Sixty percent of the patients did not achieve fT > MIC, and only 18% achieved the higher target of fT > 4נMIC. Although all the patients achieved a positive clinical outcome, the duration of antibiotic treatment was shorter in patients who achieved fT > MIC compared with those who did not (4.2 ᠱ.1 versus 5.3 ᠲ.3 days; P = 0.03). Conclusions: We found TDM to be a reliable intervention for burn injury patients in a ward environment. This study supports pharmacokinetic data that burns patients may be at risk of subtherapeutic dosing, which may prolong the duration of antibiotic therapy.