Background: This clinical trial evaluated the pharmacokinetics and safety/tolerability of amikacin/fosfomycin solution using a vibrating plate nebulizer, in mechanically ventilated patients with ventilator-associated tracheobronchitis (VAT) or ventilator-associated pneumonia (VAP).
Methods: Nine adult patients were consented to receive three escalating doses of a combination of 50 mg/mL amikacin and 20 mg/mL fosfomycin; doses were separated by 24±2 hr. On day 3, patients received two blinded, randomized treatments (amikacin/fosfomycin and volume-matched placebo), separated by 2 hr. All treatments were administered with a single-patient, multitreatment nebulizer (Investigational eFlow(®) Inline Nebulizer System; PARI Pharma GmbH, positioned in the inspiratory limb tubing between the ventilator and the patient. The nebulizer remained in-line until all treatments had been delivered. Concentrations of amikacin and fosfomycin were measured in tracheal aspirate and plasma samples obtained during the 24 hr after each dose.
Results: Fifteen minutes after dosing with the 300/120 mg amikacin/fosfomycin combination, tracheal aspirate amikacin concentrations±SD were 12,390±3,986 μg/g, and fosfomycin concentrations were 6,174±2,548 μg/g (n=6). Airway clearance was rapid. Plasma concentrations were subtherapeutic; the highest observed amikacin plasma concentration was 1.4 μg/mL, and the highest observed fosfomycin plasma concentration was 0.8 μg/mL. Administration time was approximately 2 min/mL. No adverse effects on respiratory rate, peak airway pressures, or oxygenation were observed during or following drug or placebo administration.
Conclusions: High tracheal aspirate concentrations of amikacin and fosfomycin were achieved in mechanically ventilated patients with VAT or VAP after aerosolized administration with an inline nebulizer system. Airway clearance was rapid. No adverse respiratory effects were noted during or following drug administration.
Keywords: aerosol delivery; amikacin; fosfomycin; ventilator; ventilator-associated pneumonia.