Pharmacokinetics of vancomycin in sputum of intubated patients: Optimized intravenous delivery vs. inhaled therapy.
Br J Clin Pharmacol
; 2024 Sep 05.
Article
em En
| MEDLINE
| ID: mdl-39235040
ABSTRACT
AIMS:
Intubated patients with methicillin-resistant Staphylococcus aureus pneumonia, fail optimized treatment with intravenous (IV) vancomycin (serum trough 15-20 µg/mL) in 38-79% of cases. Airway blood flow is diminished compared to alveoli and we hypothesized that vancomycin concentrations achieved in airway secretions are suboptimal and nonbactericidal. Targeted therapy by inhalation may overcome this deficit.METHODS:
Airway pharmacokinetics of optimized IV and inhaled vancomycin in infected clinically stable prolonged mechanically ventilated patients were measured. First, IV vancomycin was given until optimized concentrations were achieved (15-20 µg/mL), and, at the same time point, sputum vancomycin concentrations were measured. Then, sputum concentrations were re-assessed after 4 treatments of inhaled vancomycin (120 mg/2 mL) via a previously characterized nebulizing system that deposited 18 ± 2 mg in the lungs. Vancomycin post-distribution phase serum peak and trough concentrations were also obtained. Serum albumin was measured to assess binding to vancomycin.RESULTS:
Mean serum trough concentration was 18.4 ± 6.5 µg/mL. Sputum concentrations were affected by serum albumin. Only patients with severe hypoalbuminaemia had penetration of drug leading to therapeutic (15.7-17 µg/mL) sputum concentrations. Following inhaled vancomycin, sputum concentrations increased significantly to 199 ± 37.0 µg/mL (P = .002) exceeding minimum inhibitory concentration by 2 orders of magnitude.CONCLUSION:
Despite optimized serum concentrations, patients with albumin near normal had suboptimal concentrations of vancomycin in their sputum. Inhaled therapy may be clinically important for successful treatment of ventilator-associated methicillin-resistant Staphylococcus aureus infection. Further studies of inhaled therapy are needed to define their role as adjunctive therapy in ventilator-associated pneumonia and as single therapy in tracheobronchitis.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article