Changes of blood fentanyl concentration in rats during anhepatic phase treated by large dose of dexamethasone / 第三军医大学学报

ABSTRACT

Objective To observe the changes of blood fentanyl concentration in rats during anhepatic phase by treatment of large dose of dexamethasone and to investigate the extrahepatic metabolism of fentanyl. Methods Thirty rats were randomly divided into 3 groups (n=10 in each group): normal control group (Group A), anhepatic phase group (Group B), anhepatic phase+dexamethasone treatment group (Group C). The hepatic portal of rats was dissociated and closed in Group B. In Group C, 20 mg/kg of dexamethasone was infused 1 h before the occlusion of hepatic portal. After intravenous injection of 20 ?g/kg fentanyl each time, the blood samples were collected. The fentanyl blood concentration was analyzed by HPLC. Results The blood fentanyl concentration of anhepatic phase dropped more slowly in Group B than Group C (P0.05). Conclusion The liver is the main organ for fentanyl metabolism. There is the extrahepatic metabolism for fentanyl and dexamethasone can enhance the extrahepatic metabolism of fentanyl.