Effects of long-term alcohol exposure on the pharmacokinetic profiles of ketamine and norketamine in rats

Background: Alcohol abuse has become a serious health issue worldwide. Ketamine can reduce addiction risk among patients with alcohol use disorders. This study aimed to determine the effects of alcohol on the pharmacokinetics of ketamine during long-term alcohol exposure. Method: An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of ketamine and norketamine was developed and validated. A total of 15 rats were given 40% alcohol for 3 weeks. The pharmacokinetics of ketamine were measured at time zero, 1 week, 2 weeks, and 3 weeks after alcohol exposure. The metabolic capability of liver CYP450 was evaluated using three probe drugs: metoprolol, phenacetin, and tolbutamide. Results: During drinking of 40% alcohol, the AUC(0-t), AUC(0-infinity), and Cmax of ketamine and norketamine significantly increased, while V and CL significantly decreased with time (p < 0.001). The pharmacokinetic changes of norketamine were highly consistent with ketamine. Additionally, the concentration ratio of norketamine/ketamine in sample time also decreased over time. However, there were no pharmacokinetic changes of three probe drugs, which indicated there was no significant change of liver CYPs activities. Conclusion: Alcohol significantly increases plasma concentration of ketamine and norketamine. The effect of alcohol on pharmacokinetics of ketamine should be considered in clinical therapy. (c) 2021 Published by Elsevier Inc.