Koska A J, Romagnoli A, Kramer W G
Clin Pharmacol Ther. 1981 Jan;29(1):100-5. doi: 10.1038/clpt.1981.16.
Fentanyl kinetics was studied in two groups of six patients, one group undergoing surgery with and one without cardiopulmonary bypass; the latter served as the controls. Plasma fentanyl concentrations declined biexponentially in the control patients with an average half-life (t1/2 beta) of 3.3 +/- 1.1 hr, total plasma clearance of 11.2 +/- 3.4 ml/min/kg, and volume of distribution (Vd beta) of 3.2 +/- 1.5 l/kg. The plasma concentration/time curves were severely disrupted during cardiopulmonary bypass but appeared to regain a log-linear decay once bypass was complete. This elimination phase had a t1/2 of 5.2 +/- 2.7 hr, longer than that in the control patients. Since fentanyl is eliminated primarily by hepatic metabolism, decreased liver plasma flow observed during and after bypass, as evidenced by a 30% decrease in indocyanine green clearance, may contribute to the extended t1/2. The prolonged t1/2 had clinical importance because of potentially prolonged effects and their relation to other drugs and the clinical management of the patient.
在两组各六名患者中研究了芬太尼的动力学，一组患者进行了体外循环手术，另一组未进行体外循环手术，后者作为对照组。在对照组患者中，血浆芬太尼浓度呈双指数下降，平均半衰期（t1/2β）为3.3±1.1小时，血浆总清除率为11.2±3.4毫升/分钟/千克，分布容积（Vdβ）为3.2±1.5升/千克。在体外循环期间，血浆浓度/时间曲线严重紊乱，但一旦体外循环结束，似乎又恢复了对数线性衰减。这个消除阶段的t1/2为5.2±2.7小时，比对照组患者的t1/2长。由于芬太尼主要通过肝脏代谢消除，体外循环期间和之后观察到肝脏血浆流量减少，如吲哚菁绿清除率下降30%所证明的，这可能导致t1/2延长。t1/2延长具有临床重要性，因为其效应可能会延长，并且与其他药物以及患者的临床管理有关。
