Therapeutic Drug Monitoring in Patients With Difficult-to-Treat Gram-Negative Bacterial Infections

Upon randomization and before the bacterial culture results are known, blood sampling will be obtained from the patient during the morning round of initial empiric antibiotic administration. PK/PD target analysis based on the clinical susceptibility breakpoints of Enterobacterales (the most prevalent organism family of DT-GNB infections in our setting) will be performed and a dosage recommendation will be communicated to the primary ID clinician. Antibiotic dosing adjustments (if any) will be made within 8 - 24 hours of the blood sampling by the Primary / Infectious Diseases clinician. In case of inappropriate dosing, where the PK/PD target is not achieved or exceeded with antibiotic side effects observed, the dosage will be increased or decreased, respectively.