Strong J M, Mayfield D E, Atkinson A J, Burris B C, Raymon F, Webster L T
Clin Pharmacol Ther. 1975 Feb;17(2):184-94. doi: 10.1002/cpt1975172184.
Glycinexylidide (GX) is a metabolite of lidocaine that is frequently present in mug/ml concentrations in the plasma of patients treated with lidocaine infusions for 24 hr or more. Plasma levels of GX have 26% the antiarrhythmic activity of lidocaine in an animal model, and GX adversely affects the mental performance of normal subjects at plasma concentrations comparable to those found in patients. The total volume of GX distribution in man is similar to that of lidocaine but the plasma clearance is less, so that the 10-hr elimination phase half-life of GX is much longer than the 1 1/2 hr half-life reported in normal subjects for lidocaine. About half of an administered dose of GX is excreted unchanged in urine, roughly 15% appears in urine as conjugates of xylidine and p-OH xylidine, and the fate of the rest is unknown.
甘氨酰利多卡因（GX）是利多卡因的一种代谢产物，在用利多卡因输注治疗24小时或更长时间的患者血浆中，其浓度经常达到毫克/毫升级别。在动物模型中，GX的血浆水平具有利多卡因26%的抗心律失常活性，并且在与患者体内浓度相当的血浆浓度下，GX会对正常受试者的精神表现产生不利影响。GX在人体内的分布总体积与利多卡因相似，但血浆清除率较低，因此GX的10小时消除相半衰期比利多卡因在正常受试者中报告的1.5小时半衰期长得多。给予的GX剂量约一半以原形经尿液排出，约15%以二甲苯胺和对羟基二甲苯胺的结合物形式出现在尿液中，其余部分的去向未知。
