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)