[Kinetics of multiple-dose amikacin in the newborn infant].

Abstract

A pharmacokinetic study of amikacin was carried out in 12 neonates hospitalized in the intensive care unit. Serum amikacin levels were measured using a bacteriological method after one of several intramuscular injections of 7.5 micrograms/kg. Serum levels were greater than 10 micrograms/ml during the first three hours in 11 cases with values greater than or equal to 30 micrograms/ml. during the first two hours in five cases. The half life was measured in five patients and varied between three and eight hours. The plasma clearance was between 8.9 and 14 mil per minute per 1.73 m2. There is an unpredictable accumulation of this antibiotic especially in premature babies aged less than five days with a birth weight less than two kg. This accumulation is transitory when the clinical evolution of the case is favorable but it can be prolonged in unfavorable cases. The elimination of amikacin depends mainly on a patient's renal function. So, because of the risk of ototoxicity, the dosage should be reduced to 10 mg per kg-1 per 24 h-1, with measurements of the serum peak level and the level just before the following injection.