Aerosolized polymyxin B for treatment of respiratory tract infections: Determination of pharmacokinetic-pharmacodynamic indices for aerosolized polymyxin B against Pseudomonas aeruginosa in a mouse lung infection model

Yu Wei Lin, Qi Zhou, Nikolas J. Onufrak, Veronika Wirth, Ke Chen, Jiping Wang, Alan Forrest, Hak-Kim Chan, Jian Li

Research output: Contribution to journalArticleResearchpeer-review

16 Citations (Scopus)

Abstract

Pulmonary administration of polymyxins is increasingly used for the treatment of respiratory tract infections caused by multidrug-resistant Gram-negative bacteria, such as those in patients with cystic fibrosis. However, there is a lack of pharmacokinetics (PK), pharmacodynamics (PD), and toxicity data of aerosolized polymyxin B to inform rational dosage selection. The PK and PD of polymyxin B following pulmonary and intravenous dosing were examined in neutropenic infected mice, and the data were analyzed by a population PK model. Dose fractionation study was performed for total daily doses between 2.06 and 24.8 mg base/kg of weight against Pseudomonas aeruginosa ATCC 27853, PAO1, and FADDI-PA022 (MIC of 1 mg/liter for all three strains). Histopathological examination of the lung was undertaken at 24 h posttreatment in both healthy and neutropenic infected mice. A two-compartment PK model was required for both epithelial lining fluid (ELF) and plasma drug exposure. The model consisted of central and peripheral compartments and was described by bidirectional first-order distribution clearance. The ratio of the area under the curve to the MIC (AUC/MIC) was the most predictive PK/PD index to describe the antimicrobial efficacy of aerosolized polymyxin B in treating lung infections in mice (R2 of 0.70 to 0.88 for ELF and 0.70 to 0.87 for plasma). The AUC/MIC targets associated with bacteriostasis against the three P. aeruginosa strains were 1,326 to 1,506 in ELF and 3.14 to 4.03 in plasma. Histopathological results showed that polymyxin B aerosols significantly reduced lung inflammation and preserved lung epithelial integrity. This study highlights the advantageous PK/PD characteristics of pulmonary delivery of polymyxin B over intravenous administration in achieving high drug exposure in ELF.

Original languageEnglish
Article numbere00211-17
Number of pages15
JournalAntimicrobial Agents and Chemotherapy
Volume61
Issue number8
DOIs
Publication statusPublished - 1 Aug 2017

Keywords

  • Antibiotic resistance
  • Gram-negative bacteria
  • Polymyxins
  • Pseudomonas aeruginosa
  • Pulmonary administration
  • Respiratory tract infections

Cite this