Pharmacokinetics of amikacin in infants and pre-school children.

The pharmacokinetic properties of amikacin sulfate in infants and children aged from three weeks to 6 years were studied during treatment with doses of 7.5 mg/kg every 12 hours using standard assay methods and technique of two compartment open model kinetic analysis. Peak serum concentrations of amikacin were measured 30 or 60 min after the first intramuscular injection. These ranged from 11.8 microgram/ml to 23 microgram/ml in infants and from 9.0 microgram/ml to 29 microgram/ml in children. Five minutes after the first intravenous bolous injection they varied from 16 microgram/ml to 29.8 microgram/ml in infants and from 34 microgram/ml to 42 microgram/ml in children. Twelve hours after injection serum concentrations were less than 0.8 microgram/ml in all patients. Mean serum half-lives of amikacin in infants and children were 2.1 hours and 2.0 hours after intramuscular, and 2.2 and 2.0 hours after intravenous administration respectively. No evidence of accumulation was observed after four days treatment. The amount of antibiotic recovered within 12 hours from the urine in all patients ranged from 34.5 to 65% of an intramuscular dose, and from 45.8 to 63.3% of an intravenous dose. The dosage regime of 7.5 mg/kg body weight given every 12 hours should be safe and effective for the treatment of infections in the age groups studied.