Response of great horned owls given the optical isomers of ketamine.
The relative anesthetic effects of the 2 purified isomers and the racemic mixture of ketamine were compared in 6 great horned owls (Bubo virginianus), a species in which racemic ketamine is poorly tolerated. Other investigators have reported that the L(-) form is only a 3rd as potent as the D(+) form with respect to analgesic action in mammals. Accordingly, the racemic and the - forms were given at 2 X and 3 X, respectively, the dose of the + form in an attempt to achieve a potentially equivalent state of anesthesia. At these dose levels, there was no difference observed in the average duration of anesthesia with the 3 ketamine preparations. The - isomer yielded a poorer anesthetic response characterized by inadequate muscle relaxation, cardiac arrhythmias, and marked excitatory behavior during recovery. With the dosages used, the + form and the racemate were comparable in degree of muscle relaxation produced. The + form yielded smoother inductions and less cardiac arrhythmia than did the racemate.
D000698:Analgesia / Q000662:veterinary*; D000758:Anesthesia / Q000662:veterinary*; D000818:Animals; D001711:Biotransformation; D001717:Birds / Q000378:metabolism / Q000502:physiology*; D007103:Immobilization; D007536:Isomerism; D007649:Ketamine / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D009126:Muscle Relaxation; D051381:Rats; D011919:Rats, Inbred Strains
D007649:Ketamine