[Tobramycin Concentration in Human Lung Tissue (author's transl)]

Area of Science:

• Pharmacology
• Clinical Microbiology
• Pulmonary Medicine

Context:

• Gram-negative bacterial infections pose significant challenges in pulmonary disease management.
• Optimizing antibiotic delivery to lung tissue is crucial for effective treatment outcomes.
• Understanding drug distribution in human tissues is essential for therapeutic efficacy.

Purpose:

• To determine tobramycin concentrations in human lung tissue following intramuscular administration.
• To assess the correlation between whole blood and lung tissue tobramycin levels.
• To evaluate the suitability of intramuscular tobramycin for treating gram-negative pulmonary infections.

Summary:

• Intramuscular injection of 80 mg tobramycin results in lung tissue concentrations exceeding the minimal inhibitory concentration for most gram-negative organisms for approximately two hours.
• No detectable tobramycin was found in latissimus dorsi muscle samples within two hours post-injection.
• A 2:1 ratio of whole blood to lung tissue tobramycin concentration was observed, suggesting blood levels can estimate tissue concentrations.
• High inter-individual variability in drug levels was noted, possibly due to binding or metabolism, with no equilibrium reached within two hours.

Impact:

• Provides evidence supporting the efficacy of intramuscular tobramycin for gram-negative pulmonary infections.
• Establishes a method for estimating lung tissue tobramycin concentrations via blood level monitoring.
• Highlights the need for individualized dosing strategies due to significant pharmacokinetic variability.