[Pharmacokinetics of amikacin in the subeschar tissue fluid following severe burns]

To investigate the changes of pharmacokinetic parameters of amikacin in the subeschar tissue fluid (STF) in the early stage of severe burns.Amikacin concentration in the STF of 10 severely burned patients were determined by fluorescence polarization immunoassay (FPIA) at different time points after intravenous amikacin infusion of the initial dose of 400 mg given within 60 min. The pharmacokinetic parameters of amikacin were measured using 3P97 program and statistically analyzed with SPSS10.0 software.After the initial dose of 400 mg of amikacin, the STF concentration-time curves of amikacin were fitted in two compartment model. The pharmacokinetic parameters of amikacin in the STF were: t(1/2alpha)=(4.35-/+1.66) h, t(1/2beta)= (80.04-/+9.52) h, Vc= (13.17-/+1.32) L, AUC= (1802.49-/+285.68) microg. h.ml(-1), and CLs= (0.2272-/+0.0383) L. h(-1), demonstrating significantly lower clearance and longer elimination half life of amikacin in the STF following amikacin administration in early stage of severe burns. Elimination half-life of amikacin in the STF in severely burned patients was 28.20-44.78 times longer than that in the serum of normal volunteers, and the effective inhibitory concentration of amikacin could maintain for at least 24 h, suggesting antibiotic retention in the third space after early and short-term use of potent antibiotics and formation of antibiotic barrier in the STF, which may help prevent bacterial infection of the wound.