Stereoselective pharmacokinetics of ketamine: R(−)‐Ketamine inhibits the elimination of S(+)‐ketamine
Harald Ihmsen, Gerd Geisslinger, Jürgen Schüttler
Clinical Pharmacology & Therapeutics November 1, 2001 DOI: 10.1016/s0009-9236(01)06321-4 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized double-blind crossover study Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | Healthy young male volunteers |
| Intervention | Racemic ketamine |
| Dose | Infusion cycles with linearly increasing targets: slope 0.1 μg·ml⁻¹·min⁻¹ for S(+)-ketamine and 0.2 μg·ml⁻¹·min⁻¹ for racemic ketamine |
| Topics | Esketamine Ketamine |
| Key points | R(−)-ketamine inhibits the elimination of S(+)-ketamine, as evidenced by lower clearance of S(+)-ketamine when administered as racemic ketamine compared with the pure isomer. |
Abstract
ObjectiveWe investigated the pharmacokinetics of ketamine with special regard to enantiomer‐specific differences.MethodsTen 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‐controlled device. Two infusion cycles with linearly increasing targets [slope, 0.1 μg · ml−1 · min−1 for S(+)‐ketamine and 0.2 μg · ml−1 · min−1 for racemic ketamine] were administered. Concentrations of the ketamine enantiomers were determined from arterial blood, and pharmacokinetic parameters were estimated with a 2‐ and 3‐compartment model.ResultsThe total doses needed to reach defined end points were 271 ± 80 mg and 409 ± 75 mg for S(+)‐ketamine and racemic ketamine, respectively (P < .05). S(+)‐ketamine showed a significantly higher clearance (26.3 ± 3.5 ml · kg−1 · min−1) compared with racemic ketamine (14.8 ±1.7 ml · kg−1 · min−1; P < .05) and R(−)‐ketamine (13.8 ±1.3 ml · kg−1 · min−1; P < .05). Furthermore, the clearance of the S(+)‐ketamine was smaller in the racemate (18.5 ±0.7 ml · kg−1 · min−1; P < .05) than for the pure isomer.ConclusionsThese results demonstrate that R(−)‐ketamine inhibits the elimination of S(+)‐ketamine.Clinical Pharmacology & Therapeutics (2001) 70, 431–438; doi: 10.1016/S0009‐9236(01)06321‐4
Comparable studies
Other randomized controlled trials on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Healthy human subjects recruited from the community | 1994 | Randomized controlled trial | n = 19 |
| Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode | 2013 | Randomized controlled trial | n = 73 |
| Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Patients undergoing major abdominal surgery | 2005 | Randomized controlled trial | n = 75 |
| Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures | 2014 | Randomized controlled trial | n = 41 |
| Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Healthy volunteers | 2000 | Single-blind placebo-controlled study | n = 20 |
Citations in the library
Cited by 5
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- Simultaneous population pharmacokinetic modelling of ketamine and three major metabolites in patients with treatment‐resistant bipolar depression British Journal of Clinical Pharmacology February 1, 2012
- St John’s wort greatly decreases the plasma concentrations of oral S‐ketamine Fundamental and Clinical Pharmacology June 2, 2011
- Pharmacokinetic, pharmacodynamic, and behavioural studies of deschloroketamine in Wistar rats. British Journal of Pharmacology 2022
- KETAMINE AS AN OPTIONAL TREATMENT IN CHRONIC PAIN - A REVIEW International Journal of Innovative Technologies in Social Science September 25, 2025