[Pharmacokinetic and clinical studies on amikacin in neonates]

Pharmacokinetic and clinical studies on amikacin (AMK) were performed in neonates and the results obtained are summarized as follows. 1. After intramuscular injection of single doses of AMK at 3 mg/kg, peak serum levels were 6.8 micrograms/ml in a 2-day-old neonate and 7.0 micrograms/ml in a 20-day-old neonate. Serum levels of AMK in the above 2 neonates at 8 hours after injection were 1.5 micrograms/ml and 1.4 micrograms/ml, respectively, and the half-life of AMK was 3.3 hours. After intramuscular injection of single doses of 4 mg/kg of AMK, the mean peak serum level was 8.1 +/- 1.1 micrograms/ml, and half-lives of AMK were 6.1 hours in a 1-day-old neonate and 4.0 hours in a 3-day-old neonate. The mean peak serum level of AMK reached at 1 hour after intramuscular administrations at single dose of 6 mg/kg was 10.5 +/- 0.5 micrograms/ml in a 3-day and a 4-day-old neonates. Serum levels at 8 hours after administrations were 3.1 micrograms/ml and 2.8 micrograms/ml, in the 3-day and the 4-day-old neonates, respectively. Half-lives of AMK in sera were 3.9 hours in the 3-day-old neonate and 3.5 hours in the 4-day-old neonate. 2. In three 2-day-old neonates, the mean peak serum level of AMK after an intravenous drip infusion for 30 minutes at single dose of 3 mg/kg was 10.0 +/- 1.1 micrograms/ml at the end of infusion and serum levels decreased to 2.3 +/- 0.6 micrograms/ml at 6.5 hours after infusion.(ABSTRACT TRUNCATED AT 250 WORDS)