Modification by ketamine on the neuromuscular actions of magnesium, vecuronium, pancuronium and alpha-bungarotoxin in the primate.
The neuromuscular effects of ketamine, at cumulative doses of 2.5 and 10 mg.kg-1 iv, were studied by electromyographically quantifying the thumb response evoked by ulnar nerve stimulation in 25 monkeys anaesthetized with pentobarbital-N2O-O2. Ketamine alone at these doses had no neuromuscular effects. When the EMG response was maintained at 50% of control by a continuous infusion of magnesium, vecuronium, or pancuronium, ketamine depressed the responses by an additional 13 +/- 3%, 34 +/- 7% and 32.5 +/- 3.3% (mean +/- SEM), respectively, at the highest dose, P less than 0.05. In contrast, ketamine had no effect on the neuromuscular block produced by incremental doses of alpha-bungarotoxin. These results indicate that ketamine does not act on the postjunctional acetylcholine receptor. It plays a secondary role in neuromuscular block, possibly by prejunctional or postjunctional effects independent of receptor occupation.
Department of Anesthesiology, Harbor-UCLA Medical Center, Torrance 90509.
S K
SK
Tsai
K T
KT
Liao
C M
CM
Lee
D000818:Animals; D002038:Bungarotoxins / Q000494:pharmacology*; D003864:Depression, Chemical; D007649:Ketamine / Q000494:pharmacology*; D008251:Macaca; D008278:Magnesium Sulfate / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects*; D010197:Pancuronium / Q000494:pharmacology*; D014673:Vecuronium Bromide / Q000494:pharmacology*
D002038:Bungarotoxins; D007649:Ketamine; D008278:Magnesium Sulfate; D014673:Vecuronium Bromide; D010197:Pancuronium