Stereoselective pharmacokinetics of ketamine: R(−)‐Ketamine inhibits the elimination of S(+)‐ketamine
Clinical Pharmacology & Therapeutics November 1, 2001 Harald Ihmsen, Gerd Geisslinger, Jürgen Schüttler
In a randomized double-blind crossover study, ten healthy young men received racemic ketamine and S(+)-ketamine via computer-controlled infusion. S(+)-ketamine required a lower total dose to reach defined endpoints (271 ± 80 mg) compared with racemic ketamine (409 ± 75 mg). S(+)-ketamine had significantly higher clearance (26.3 ± 3.5 ml·kg⁻¹·min⁻¹) than racemic ketamine (14.8 ± 1.7) and R(−)-ketamine (13.8 ± 1.3). Within the racemate, S(+)-ketamine clearance was lower (18.5 ± 0.7) than when given alone. The authors conclude that R(−)-ketamine inhibits the elimination of S(+)-ketamine.