Lauven P M, Stoeckel H, Schüttler J, Schwilden H
Anaesthesist. 1981 Sep;30(9):467-71.
Pre- and intraoperatively 8 orthopaedic patients were given cimetidine in order to raise the pH of gastric juice. Following an 0.5 mg i.v. bolus injection of fentanyl at the beginning of anaesthesia, the pH of the gastric juice and plasma concentrations of fentanyl were measured. After oral medication with cimetidine 400 mg on the evening prior to anaesthesia and an i.v. administration of 200 mg/h during the course of an enflurane-N2O-anaesthesia no secondary peak of plasma fentanyl concentration was observed. Thus it would seem possible to prevent fentanyl sequestration into the stomach and consecutively gastro-entero-systemic recirculation by administration of cimetidine. While duration and half-life of the alpha-phase are prolonged, the half-life of the beta-phase (150 min) remains almost unchanged. This pharmacokinetic effect is explained by an altered biodisposition.
术前及术中，8例骨科患者接受西咪替丁治疗，以提高胃液pH值。麻醉开始时静脉注射0.5毫克芬太尼推注后，测量胃液pH值和芬太尼血浆浓度。在麻醉前一晚口服400毫克西咪替丁，并在恩氟烷 - N₂O麻醉过程中静脉输注200毫克/小时后，未观察到血浆芬太尼浓度的二次峰值。因此，通过给予西咪替丁似乎有可能防止芬太尼在胃中滞留并进而防止胃肠 - 全身再循环。虽然α相的持续时间和半衰期延长，但β相的半衰期（150分钟）几乎保持不变。这种药代动力学效应是由生物处置改变所解释的。
