Pharmacokinetics of gentamicin administered intratracheally to rats

The pharmacokinetics of intratracheally instilled and intravenously injected gentamicin were compared in the rat and analyzed by a one-compartment open model. The maximum concentration of gentamicin in plasma occurred within 10 min after intratracheal instillation. Considerable amounts of gentamicin were absorbed from lungs after intratracheal instillation, as shown by its concentrations in plasma and elimination in urine. The data suggest that the absorption of gentamicin from the pulmonary system would be sufficient to maintain therapeutic levels of this agent in plasma.