Stereoselective pharmacokinetics of ketamine and norketamine after racemic ketamine or S-ketamine administration during isoflurane anaesthesia in Shetland ponies

Abstract

Norketamine enantiomers showed different pharmacokinetic profiles after single i.v. administration of racemic ketamine in ponies anaesthetised with isoflurane in oxygen (1 MAC). Cardiopulmonary variables require further investigation.

Enantioselective analysis of ketamine and its metabolites in equine plasma and urine by CE with multiple isomer sulfated β‐CD

“…No statistical difference was noted for the norketamine enantiomers during the infusion time period (P .0.05). However, plasma concentrations of Snorketamine were significantly higher than plasma concentrations of R-norketamine at the time points after the end of infusion (P ,0.05), which is comparable with the results obtained after bolus injection of racemic ketamine [11]. It is interesting to note that P values were found to decrease for the samples collected during the infusion time period (P = 0.1807 and 0.0590 for samples collected at 10 and 120 min, respectively).…”

“…Analyses were performed in an untreated fused-silica capillary and having reversed polarity, indicating that the migrating drug complexes have a negative charge (strong complexation). A typical electropherogram obtained with ketamine and norketamine standards and the sulfated b-CD of Aldrich, lot 07222HO which was employed in our previous work [10][11][12], is presented in Fig. 2A.…”

“…The pharmacokinetic data and clinical analgesic effects of S-and R-ketamine, however, are poorly documented for this species [9]. Thus, interdisciplinary research efforts were undertaken at our University to assess the use of racemic ketamine versus S-ketamine for anesthesia and pain therapy in horses, work that required the development of a stereoselective assay for the monitoring of plasma levels of ketamine and norketamine enantiomers [10], and led to the pharmacokinetic description of the biotransformation of ketamine to norketamine after bolus injection [11] and target-controlled infusion [12].…”

CE provides evidence of the stereoselective hydroxylation of norketamine in equines

“…Thus, interdisciplinary research efforts are undertaken to assess the use of ketamine (as racemic mixture) versus S-ketamine for anesthesia and pain therapy in horses. This work required the development of stereoselective assays for a variety of applications [25][26][27][28][29][30][31]. Enantioselective CE assays were found to be attractive approaches for the assessment of the stereoselectivity of drug metabolism [32][33][34].…”

Stereoselective determination of drugs and metabolites in body fluids, tissues and microsomal preparations by capillary electrophoresis (2000–2010)

“…As with our previous compilation 10 years ago [26], insight into the achievements is presented via distinction between enantiomer analysis in fortified body fluids (Table 1), body fluids and tissues of humans and animals (Tables 2 and 3), in vitro preparations (Table 4) and in forensic biosamples (Table 5 [ ). Furthermore, the stereoselective CE work associated with a multidisciplinary ketamine project is presented separately (Table 6 [ [154][155][156][157][158][159][160][161][162][163][164][165][166][167][168][169]). Major focus is given on systems in which stereoisomers of parent drug and metabolites are analyzed together in one run.…”