Optimal dosing regimen of biapenem based on population pharmacokinetic/pharmacodynamic modeling and Monte Carlo simulation in Febrile Neutropenic Patients with Hematologic Malignancies

In the current study, a population pharmacokinetic (PPK) model was developed for biapenem in patients with febrile neutropenia (FN) who have hematological malignancies. Through Monte Carlo simulation, optimal administration regimens were suggested based on the developed PPK model. In a perspective, single-center, open-label study, 174 plasma samples from 120 Chinese patients with FN having hematological malignancies were analyzed by chromatography, and PK parameters were analyzed by NONMEM®. The drug clearance process was influenced by crucial covariates, namely creatinine clearance rate (CLCR) and concomitant posaconazole (POS). The ultimate PPK model was as follows: CL (L/h) = 29.81 × (CLCR/121.38)^0.806 × (1-POS × 0.297); V(L) = 114. For the target of ≥40% fT > minimum inhibitory concentration (MIC) (the duration that the plasma level exceeds the MIC of the causative pathogen) and achieving the probability of target attainment ≥90%, the PK/pharmacodynamic breakpoint was 2 mg/L for the 2.4 g/d-dosing regimen consisting of 600 mg q6h and 800 mg q8h. The breakpoint was 1 mg/L for the 1.2 g/d-dosing regimen consisting of 300 mg q6h and 600 mg q12h. Empirical therapy would benefit from utilizing higher dosages and extended infusion durations. Therefore, it is suggested that patients with symptoms that are strongly suspected of Pseudomonas aeruginosa or Acinetobacter baumannii infections may be suitable for combined treatment with other antibacterial drugs.