Zarowitz B J, Peterson E L, Robert S
Henry Ford Hospital, Department of Pharmacy, Detroit, Michigan.
Med Prog Technol. 1993;19(4):193-8.
Bioelectrical impedance analysis (BIA) yields accurate, safe and non-invasive estimates of body composition in humans. Pharmacokinetic characterization of drugs represents the body as a series of non-physiologic compartments. We evaluated the utility of BIA in the pharmacokinetic characterization and dosing of water soluble drugs. Serial serum concentrations of gentamicin (G) in 30 hospitalized adults, and theophylline (T), in 15 normal adult males were obtained over a dosing interval after an 8h fast, and analyzed in duplicate by enzyme-mediated immunoassay technique. BIA was performed serially in duplicate during the same time period using a fixed frequency (50kHz, 800 microA) current-injection 4-electrode plethysmograph. Multiple regression techniques were used to develop descriptive models of pharmacokinetic parameters which yielded equations with p-values < 0.03 and coefficients of variation < 20% accounting for > 85% of the pharmacokinetic variability. The G models were then tested in 20 critically ill adults at steady state by serum concentration measurement (criterion standard) and BIA. BIA predictive equations yielded pharmacokinetic parameters not different (by paired t-tests) than those derived by serum concentration measurement. While BIA is an innovative approach to the non-invasive characterization water soluble drugs, further testing with variable frequency BIA under perturbed conditions is warranted.
生物电阻抗分析（BIA）能够准确、安全且无创地评估人体的身体成分。药物的药代动力学特征将人体视为一系列非生理性的房室。我们评估了BIA在水溶性药物药代动力学特征分析和给药方面的效用。在30名住院成人中，于禁食8小时后的给药间隔内获取庆大霉素（G）的系列血清浓度；在15名正常成年男性中，获取茶碱（T）的系列血清浓度。采用酶介导免疫测定技术对样本进行双份分析。在同一时期内，使用固定频率（50kHz，800微安）电流注入式四电极体积描记器对BIA进行双份连续测量。运用多元回归技术建立药代动力学参数的描述性模型，所得方程的p值<0.03，变异系数<20%，可解释>85%的药代动力学变异性。随后，通过血清浓度测量（标准对照）和BIA对20名病情危重的成年患者在稳态下对G模型进行测试。BIA预测方程得出的药代动力学参数与通过血清浓度测量得出的参数无差异（通过配对t检验）。虽然BIA是一种用于无创表征水溶性药物的创新方法，但仍需在受干扰条件下使用可变频率BIA进行进一步测试。
