[Diffusion of amikacin in the lungs]

The authors report their findings on amikacin concentrations in serum and in the lungs, its diffusion in the parenchyma of the lungs--evaluated from the ratio tissue/serum concentrations, and they also compare their results with those registered during a study on dibekacin, tobramycin and netilmicin, designed according to the same protocol. Ten patients with bronchial carcinoma who had to undergo chirurgical excision, received 5 IM injections at 12-hourly intervals. The dose administrated at each injection was 7.5 mg/kg. The assay of amikacin was realized by HPLC. Serum concentrations at the presumed peak (17 micrograms/ml) and 12 hours after that were somewhat lower than those reported by other authors. The mean tissue concentrations 2 h 20 min. after the last injection were 14,95 +/- 4,52 micrograms/g in the normal parenchyma, and 16,18 +/- 3,67 micrograms/g in the pathological parenchyma. The ratio concentrations in the tissues and in serum were comparable for both the normal and pathological parenchyma. Compared to dibekacin, tobramycin and netilmicin, this study confirms the large distribution of the aminoglycosides in the lung parenchyma. The behaviour of dibekacin and tobramycin with regard to the pathological parenchyma is rather comparable; netilmicin better penetrates into the normal parenchyma, and the diffusion of amikacin is parallel for both the normal and pathological tissues.