Bronchial secretion levels of amikacin

Area of Science:

• Pharmacology
• Pulmonology
• Infectious Diseases

Background:

• Amikacin is an aminoglycoside antibiotic used for serious bacterial infections.
• Understanding amikacin penetration into bronchial secretions is crucial for treating respiratory infections.

Purpose of the Study:

• To determine amikacin concentrations in serum and bronchial secretions.
• To assess the correlation between serum and bronchial secretion levels.
• To evaluate the duration of amikacin presence in bronchial secretions.

Main Methods:

• 14 noninfected men received intramuscular amikacin (7.5 mg/kg) every 12 hours.
• Serum and bronchial secretion samples were collected via bronchoscopy after the final dose.
• Concentrations were measured at various time points, with analysis of correlation and elimination half-life.

Main Results:

• Peak serum amikacin levels (1.5-2.0 h post-dose) averaged 23.7 µg/ml, while bronchial secretion levels averaged 5.23 µg/ml.
• A strong positive correlation was observed between serum and bronchial secretion concentrations (r=0.82).
• Elimination half-lives were similar in serum (2.84 h) and bronchial secretions (2.60 h).
• After 7 hours, bronchial secretion levels dropped below 1.0 µg/ml.

Conclusions:

• Amikacin can achieve concentrations potentially effective against some gram-negative bacteria in bronchial secretions 1-2 hours after dosing.
• However, levels may not be sufficient against Pseudomonas aeruginosa.
• Rapid decline necessitates careful consideration of dosing intervals for effective treatment.