[Pharmacokinetic and clinical studies of latamoxef in newborn and premature infants].

The authors have carried out the pharmacokinetic and clinical studies of latamoxef (LMOX) in mature and premature neonates. The results were as follows. The serum mean peak levels of LMOX after intravenous administration at a single dose of 10 mg/kg (20 mg/kg) were 40.7 +/- 20.8 (76.6 +/- 12.7) micrograms/ml in 1 to 3 day-old-neonates, 39.3 +/- 29.3 (52.5 +/- 6.6) micrograms/ml in 4 to 7 day-old-neonates and 26.0 +/- 2.1 (47.4) micrograms/ml in 8 to 15 day-old neonates at 15 minutes. The serum mean levels at 6 hours after dosage were 12.5 +/- 5.2 (25.6 +/- 9.2) micrograms/ml, 10.3 +/- 5.3 (11.8 +/- 1.6) micrograms/ml and 4.2 +/- 0.9 (7.2) micrograms/ml, respectively. The mean half-life times were 4.25 (6.0) hours in 1 to 3 day-old-neonates, 3.4 (3.3) hours in 4 to 7 day-old-neonates and 2.2 (2.2) hours in 8 to 15 day-old-neonates. The serum levels of LMOX after intravenous drip infusion for 30 minutes at a single dose of 10 mg/kg were 17.6 micrograms/ml at completion of infusion, 6.9 micrograms/ml at 6.5 hours, and the half-life was 3.8 hours in 2 day-old-mature neonates. In 3 day-old-premature neonates, the serum levels were 21.1 micrograms/ml at the completion of infusion, 12.7 micrograms/ml at 6.5 hours, and the half-life was 12.2 hours. After intravenous drip infusion for 30 minutes a single dose of 20 mg/kg of LMOX the serum mean levels were 58.5 +/- 6.4 micrograms/ml at the completion of infusion, 19.3 +/- 1.1 micrograms/ml at 6.5 hours, respectively. The half-life times were 4.0 hours in 2 day-old-neonates and 4.5 hours in 4 day-old-neonates. The urinary excretion rate of LMOX in 3 day-old-neonate was 31.7% up to 6 hours after intravenous administration at a single dose of 10 mg/kg. LMOX were clinically effective in a case of pneumonia, but not effective in a case of septicemia. No side effect was observed except for 1 case with elevation of GOT.