Metabolism of ketamine stereoisomers by human liver microsomes
Ketamine N-demethylation by microsomes from three human livers was measured by gas chromatography-mass spectrometry. At ketamine concentrations typically achieved during anesthesia (5 microM), the rate of S(+) ketamine demethylation was 20% greater than that of R(-) ketamine and 10% greater than that of the racemate (P < .05).
Comparison of ketamine stereoisomers on tissue metabolic ... - PubMed
Since ketamine is optically active, we compared the neuroprotective efficacy of the (+)- or (-)-enantiomers in global cerebral ischaemia. Rat corticostriatal slices superfused with, or incubated in, artificial CSF at 34 degrees C were subjected to a brief ischaemic insult.
Comparison of ketamine stereoisomers on tissue metabolic …
2001年4月1日 · Ketamine comprises two stereoisomers of which only one, (+)-ketamine, is separately available for clinical usage. The (+)-isomer is the more potent anaesthetic ( Engelhardt et al., 1998) and analgesic ( Ryder et al., 1978 ). There are also striking differences in other aspects of the pharmacology of the two enantiomers.
The R-Stereoisomer of Ketamine as an Alternative for Ketamine …
2014年12月1日 · Taken together, these data suggest that the R-stereoisomer of ketamine would be an alternative antidepressant for ketamine as R-ketamine may be free of psychotomimetic side effects.
Ketamine enantiomers in the rapid and sustained antidepressant effects ...
Stereoisomerism and ketamine. Ketamine is a good example to illustrate how subtle changes in stereoisomerism can result in significant changes in structure–activity relationships [Modica et al. 1990]. The pharmacological profile of racemic ketamine is characterized by the so-called dissociative anesthetic state and profound sympathomimetic ...
Stereoselective pharmacokinetics of ketamine: R(-)-ketamine …
Objective: We investigated the pharmacokinetics of ketamine with special regard to enantiomer-specific differences. Methods: Ten healthy young male volunteers (mean age, 28 +/- 4 years; mean weight, 79 +/- 11 kg) received racemic ketamine and S(+)-ketamine in a randomized double-blind crossover study. Drugs were administered by a computer ...
Ketamine Distribution Described by a Recirculatory Pharmacokinetic ...
Although the elimination clearance of S-(+)-ketamine is 35% greater than that of the R-(-)-enantiomer, there is no difference in the apparent pulmonary tissue volume or peripheral tissue distribution between the stereoisomers, suggesting that physicochemical properties of ketamine other than stereoisomerism determine its perfusion-limited ...
Ketamine Pharmacology: An Update (Pharmacodynamics and …
Ketalar ® is the racemic mixture (optically inactive) of 2 enantiomers of equal quantity (isomers that diverge light in opposite ways). The active enantiomer is S (+)‐ketamine (“S” spatial structure, light diverged to the right), two times stronger than the racemic form, and four times than the R (−)‐ketamine isomer.
Ketamine - Hodder Education Magazines
Ketamine has two stereoisomers, (R)-ketamine and (S)-ketamine (Figure 1). They are enantiomers — stereoisomers that are non-superimposable mirror images of each other, due to ketamine having an asymmetric carbon in its structure.
Metabolism of ketamine stereoisomers by human liver microsomes.
Metabolism of ketamine stereoisomers by human liver microsomes. Ketamine is used clinically as a racemic mixture of optical isomers that differ in their analgesic properties and psychomimetic effects. Administered individually, or together as the racemate, ketamine enantiomers differ in their hepatic clearance and duration of anesthetic effect.