Pharmacokinetics and bronchial diffusion of single daily dose amikacin in cystic fibrosis patients.

A single daily dose of amikacin 35 mg/kg by i.v. infusion over 30 min in 18 cystic fibrosis patients achieved mean serum peak and trough concentrations of 121.4 mg/L (+/- 37.3) and 0.88 mg/L (+/- 0.62), respectively. Pharmacokinetic parameters and bronchial diffusion of amikacin showed marked inter-patient variability. The highest concentrations in sputum were obtained at 2 h (10.95 +/- 7.55 mg/L) and decreased slowly to reach a mean concentration of 2.14 mg/L (range 0.2-3.8 mg/L) just before the following infusion. An increase in the body clearance of amikacin and a decrease in the volume of distribution according to age were observed.