庆大霉素和阿米卡星在老年人中的药代动力学研究

STUDY ON PHARMACOKINETICS OF GENTIMICINAND AMIKACIN IN THE ELDERLY

为了提供氨基糖甙类抗生素庆大霉素和阿米卡星在老年人感染时合理给药方案的依据，我们对两种药物在老年人中的药代动力学进行了研究，并与年轻人进行了对照比较。采取微生物琼脂弥散法测定其药物浓度。老年组用单剂量静滴庆大霉素１２０ｍｇ后的消除半衰期（Ｔ１／２β）为３．５２±０．７３ｈ，肾清除率（ＣＬｒｅｎａｌ）为２．６６±０．８２Ｌ·ｈ－１，药时曲线下面积（ＡＵＣ）为３１．００±６．９７ｍｇ·ｈ·Ｌ－１。２４ｈ累积尿排出率（ＵＥＲ）为６４．７１±８．８１％。老年组用单剂量静滴阿米卡星４００ｍｇ后的Ｔ１／２β为３．１２±０．４４ｈ，ＣＬｒｅｎａｌ为２．７９±０．６４Ｌ·ｈ－１，ＡＵＣ为９９．９±２０．２９ｍｇ·ｈ·Ｌ－１，ＵＥＲ为６７．２５±７．０２％。因此老年组无论是接受庆大霉素或阿米卡星，与年轻组相比Ｔ１／２β明显延长，ＣＬｒｅｎａｌ降低，ＡＵＣ值升高以及ＵＥＲ降低。两组间上述参数差异均有统计学意义（Ｐ＜０．０５或Ｐ＜０．０１）。老年人感染应用庆大霉素或阿米卡星时需减少给药剂量和延长给药间期。

In order to be proposed a therapeutic regimen for the rational use of gentamicin and amikacin in the elderly, the pharmacokinetic study of both drugs was carried out and compared with that in the younger. The drug concentrations were measured by bioassay. After a single dose of 120 mg gentamicin by iv infusion administration in the elderly, the elimination half-life (T1/2β), renal clearance (CLrenal), the area under curve (AUC) and cumulative urinary recovery rate (UER) within 24 h were 3.52±0.73 h , 2.66±0.82 L·h-1 , 31.00±6.97 mg·h·L-1 and 64.71±8.81%,respectively. After a single dose of 400 mg amikacin by iv infusion administration in the elderly, T1/2β, CLrenal, AUC and UER were 3.12±0.44 h,2.79±0.64 L·h-1 , 99.90±20.29 mg· h ·L-1 and 67.25±7.02%,respectively. Obviously, T1/2β was longer, CLrenal was lower, AUC was larger in the elderly after a single dose of gentamicin or amikacin than that in the younger. The differences of those above parameters between two groups were statistically significant. In conclusion, the reduction of dose and prolongation of intervals should be considered for gentamicin and amikacin in the treatment of infections in the elderly.