de Repentigny L, Dumont L, Le Lorier J, Morisset R, Larochelle P, Courchesne Y
Can Med Assoc J. 1981 Jun 1;124(11):1459-63.
Gentamicin, an antibiotic frequently used in the treatment of gram-negative infections, has a narrow therapeutic index, so the correct prediction of its serum concentrations is important. Recent studies have emphasized the dubious accuracy of commonly used formulas, and computer programs that provide pharmacokinetic data for individual patients from multiple blood samples have helped to adjust dosages but are expensive. This study tested the applicability of a method using only two blood samples and a programmable calculator to estimate pharmacokinetic parameters for individual patients and adjust dosages to aim at peak and trough serum levels of 6 and 1 micrograms/ml respectively. In the 48 patients with normal renal function this method produced peak serum concentrations of gentamicin within 1 microgram/ml of the desired level in 22 (46%) and therapeutic peak concentrations (between 4 and 10 micrograms/ml) in all the patients. In 10 patients with renal failure it produced peak serum concentrations within 1 microgram/ml of the desired value in 4 and therapeutic serum concentrations in 7. Two patients had peak concentrations below 4 micrograms/ml and one had a peak concentration above 10 micrograms/ml. Two of the three patients whose serum levels were outside the therapeutic range had unstable renal insufficiency. Thus, patients with renal insufficiency need continued monitoring of the serum level of gentamicin, particularly when their renal function is changing.
庆大霉素是一种常用于治疗革兰氏阴性菌感染的抗生素，其治疗指数较窄，因此准确预测其血清浓度很重要。最近的研究强调了常用公式的准确性存疑，而通过多个血样为个体患者提供药代动力学数据的计算机程序虽有助于调整剂量，但成本高昂。本研究测试了一种仅使用两份血样和可编程计算器来估算个体患者药代动力学参数并调整剂量，以使血清峰浓度和谷浓度分别达到6微克/毫升和1微克/毫升的方法的适用性。在48例肾功能正常的患者中，该方法使22例（46%）患者的庆大霉素血清峰浓度达到所需水平的1微克/毫升以内，且所有患者的治疗峰浓度（4至10微克/毫升之间）均达标。在10例肾衰竭患者中，该方法使4例患者的血清峰浓度达到所需值的1微克/毫升以内，7例患者达到治疗血清浓度。2例患者的峰浓度低于4微克/毫升，1例患者的峰浓度高于10微克/毫升。血清水平超出治疗范围的3例患者中有2例存在不稳定的肾功能不全。因此，肾功能不全患者需要持续监测庆大霉素的血清水平，尤其是在其肾功能发生变化时。
