PHARMACOKINETICS OF AMIKACIN IN INTENSIVE-CARE UNIT PATIENTS

Objective: To characterize the population pharmacokinetics of amikacin in intensive care unit (ICU) patients and to analyse whether these pa tients show different kinetic behaviour on the basis of their clinical diagnoses. Method: The patient population comprised 104 medical ICU p atients on amikacin treatment for several presumed or documented Gram- negative infections. Four study groups were defined according to patie nts' clinical diagnosis: sepsis group (n=39), trauma group (n=20), pne umonia group (n=21) and 'other diagnosis' group (n=24). The pharmacoki netic parameters for amikacin in these patients were then compared. Re sults: The ICU patients were found to have increased values for the am ikacin volume of distribution (0.52 +/- 0.21 litres/kg), whereas total amikacin clearance expressed as a linear function of creatinine clear ance was CI (ml/min/kg)=0.13 + 0.86 Cl-CR which is not significantly d ifferent from other estimations reported in the literature. However, t his relationship revealed statistically significant differences among the four groups of ICU patients. Moreover, the septic and trauma patie nts showed higher (but not statistically significant) values for the a mikacin volume of distribution. Conclusion: The amikacin pharmacokinet ic parameters obtained should allow Bayesian individualization of amik acin doses in patients admitted to medical ICUs, on the basis of their clinical diagnoses.