Bourgeois B F, Dodson W E
Neurology. 1983 Feb;33(2):173-8. doi: 10.1212/wnl.33.2.173.
We measured the apparent half-life (t50%) of phenytoin (PHT) 30 times in 16 infants (aged 2 to 36 days) who had seizures. During the first week of life, the t50%s ranged from 6 to 140 hours. After the first week, the concentration dependence of PHT elimination was demonstrated; the t50% was related to the initial concentration (Ci). The t50% also decreased with postnatal age. Controlling for a Ci of 18 mg per liter, the average t50% decreased threefold between the first (57.3 +/- 48.2 hours) and fourth weeks (19.7 +/- 1.31). In newborns, both age-related changes and the concentration dependence of PHT elimination can cause PHT levels to decrease when constant doses are given.
我们对16名患有癫痫的婴儿（年龄在2至36天之间）进行了30次苯妥英（PHT）的表观半衰期（t50%）测定。在出生后的第一周内，t50%范围为6至140小时。第一周之后，显示出PHT消除的浓度依赖性；t50%与初始浓度（Ci）相关。t50%也随着出生后的年龄增长而降低。在控制Ci为每升18毫克的情况下，平均t50%在第一周（57.3±48.2小时）和第四周（19.7±1.31小时）之间下降了三倍。在新生儿中，当给予恒定剂量时，与年龄相关的变化以及PHT消除的浓度依赖性均可导致PHT水平降低。
