Routledge P A, Lazar J D, Barchowsky A, Stargel W W, Wagner G S, Shand D G
Br J Clin Pharmacol. 1985 Dec;20(6):695-8. doi: 10.1111/j.1365-2125.1985.tb05132.x.
A free lignocaine index was developed on the basis of measurements of plasma lignocaine and its principle binding protein, alpha 1-acid glycoprotein (AAG) in 80 samples from 16 patients admitted to the coronary care unit and given prophylactic lignocaine therapy. The free drug fraction, fu, of lignocaine was determined by equilibrium dialysis and its relationship to AAG and total lignocaine concentration (T) defined by multiple linear regression analysis as l/fu = 1.45 + 0.023 (AAG) -0.129 (T) (multiple r = 0.872, P less than 0.001). This relationship was used to calculate the 'free lignocaine index' as fu X T and compared with the observed value obtained by equilibrium dialysis of 178 samples from 41 separate subjects who received lignocaine after suspected myocardial infarction. There was a highly significant relationship (r = 0.933, n = 178, P less than 0.001) between the observed and predicted values. We conclude that the free drug index may be useful in rapidly assessing the unbound (free) concentration of lignocaine in plasma.
在对16名入住冠心病监护病房并接受预防性利多卡因治疗的患者的80份样本进行血浆利多卡因及其主要结合蛋白α1 - 酸性糖蛋白（AAG）测量的基础上，制定了游离利多卡因指数。通过平衡透析法测定利多卡因的游离药物分数fu，并通过多元线性回归分析确定其与AAG和总利多卡因浓度（T）的关系为1/fu = 1.45 + 0.023（AAG） - 0.129（T）（复相关系数r = 0.872，P < 0.001）。利用这种关系计算“游离利多卡因指数”，即fu×T，并将其与41名单独受试者在疑似心肌梗死后接受利多卡因治疗的178份样本通过平衡透析获得的观测值进行比较。观测值与预测值之间存在高度显著的关系（r = 0.933，n = 178，P < 0.001）。我们得出结论，游离药物指数可能有助于快速评估血浆中利多卡因的未结合（游离）浓度。
