Pharmacokinetics and Safety of Esketamine in Chinese Patients Undergoing Painless Gastroscopy in Comparison with Ketamine: A Randomized, Open-Label Clinical Study

Jing Wang,1,2,* Jie Huang,1,3,* Shuang Yang,1,3 Chang Cui,1,3 Ling Ye,1,3 Sai-ying Wang,4 Guo-ping Yang,1,3 Qi Pei1,2 1Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, People’s Republic of China; 2Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, People’s Republic of China; 3Clinical Trails Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, People’s Republic of China; 4Department of Anesthesiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, People’s Republic of China*These authors contributed equally to this workCorrespondence: Guo-ping Yang; Qi PeiThe Third Xiangya Hospital, Central South University, Yinpenling Street, Yuelu District, Changsha, Hunan 410013, People’s Republic of ChinaTel +86 131 7041 9804Fax +86 731 8861 8326Email ygp9880@126.com; peiqi1028@126.comPurpose: To assess the pharmacokinetics and safety of pure S-ketamine (esketamine) in Chinese patients undergoing painless gastroscopy and evaluate the potential advantage of esketamine in clinical treatment compared with racemate ketamine hydrochloride injection.Patients and methods: A randomized, open-label, parallel-controlled, Phase I study was performed with 32 patients undergoing painless gastroscopy. Patients received a single dose of esketamine (0.5 mg/kg) or racemic ketamine (1 mg/kg, esketamine:R-ketamine=1:1), injected in 10 s. Blood samples were collected for pharmacokinetic analysis. The concentrations of esketamine, R-ketamine, S-norketamine, and R-norketamine were measured with a validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) method.Results: After administering a single dose of esketamine and racemate ketamine, the pharmacokinetics parameters of esketamine and S-norketamine are both similar in treatment groups. The clearance of esketa