@entity2756 kinetics were characterized after a single, 2-minute, intravenous infusion of 50 mg/kg to 20 sick @entity1 1 to 8 days old who weighed 1.78 to 4.36 kg. Plasma binding parameters could be determined by equilibrium dialysis in 16 of the @entity1 , in whom kinetic parameters for free @entity2756 in plasma were also determined. Compared with corresponding values in adults, the elimination t1/2 was longer in @entity1 (19 and 8.4 hours) because of reduced total systemic clearance (4.48 and 8.51 ml/min/m2). The apparent steady-state volume of distribution was of the same order in @entity1 and adults (5,130 and 5,350 ml/m2). Both renal and nonrenal clearance of free @entity2756 were reduced in @entity1 , but these decreases were partially offset by an increased free fraction; plasma binding affinity and capacity constants for @entity1 were about half the adult values. The mean fraction of dose excreted unchanged in urine was estimated at 70% in the neonates and 46% in adults. There were no clinically significant correlations between the kinetic parameters and either age since birth or age since conception. The fraction of free @entity2756 in plasma inversely correlated with age since conception and was lower in female @entity1 , which decreased the systemic clearance and volume of distribution of total drug in the female @entity1 compared with the male @entity1 . Values for the volume of distribution and clearance parameters were not related to body size (weight or body surface area). From our results, a @entity2756 dosage of 50 to 100 mg/day is recommended during the first week of life for newborn @entity1 who weigh between 1.8 and 4.4 kg. @entity8 may require a reduction in dosage.

Single-dose XXXX kinetics in the newborn.

@entity1 :: ('9606', 'Species') :: ['infants'] @entity2756 :: ('MESH:D002443', 'Chemical') :: ['ceftriaxone', 'Ceftriaxone'] @entity8 :: ('MESH:D007674', 'Disease') :: ['Impaired renal function']
@entity2756 :: (MESH:D002443,Chemical) :: ['ceftriaxone']
