Yoshioka H, Takimoto M, Shimizu T, Haga H
Infection. 1979;7(1):27-9. doi: 10.1007/BF01640553.
A 500 mg intramuscular dose of carbenicillin produced peak levels averaging 147 microgram/ml after three hours in the first day full-term newborn infants, and 172 microgram/ml after one to two hours in infants five days of age. The fall of blood levels thereafter was delayed and serum half-life averaged 4.2 and 2.2 hours in both groups, almost four times and twice as long, respectively, as that reported in adults. Absorption from the injected site was also delayed in young newborns, as was shown by the delayed serum peak and small estimated absorption rate constant. This must be taken into consideration if the intramuscular route is chosen in young newborn infants. On the basis of serum half-life, an administration interval of 12 hours was recommended for newborns younger than four days, and eight hours for those five days of age or more.
在足月新生儿出生第一天，肌肉注射500毫克羧苄青霉素后，三小时达到的峰值平均为147微克/毫升；而在出生五天的婴儿中，一至两小时达到的峰值平均为172微克/毫升。此后两组血药浓度下降均延迟，血清半衰期分别平均为4.2小时和2.2小时，几乎分别是成人报告值的四倍和两倍。年轻新生儿注射部位的吸收也延迟，血清峰值延迟和估算的吸收速率常数较小就表明了这一点。如果给年轻新生儿选择肌肉注射途径，这一点必须考虑在内。根据血清半衰期，建议出生四天以内的新生儿给药间隔为12小时，五天及以上的新生儿给药间隔为8小时。
