Discrepancy of recovery times related to potency between atracurium and mivacurium simultaneously administered in isolated forearms.
Recovery from potent non-depolarising muscle relaxants is slower than from the less potent agents. However, recovery from mivacurium, which is more potent than atracurium, is faster than from atracurium following systemic administration. In an attempt to confirm this discrepancy we compared recovery times following simultaneous administration of equipotent doses of atracurium and mivacurium into the isolated forearms of human volunteers (n = 10). This method enabled us to study the interaction of muscle relaxants with receptors at the neuromuscular junction separated from the effects of plasma drug concentration. In these experiments, the recovery times from maximum block to 50% recovery of control twitch height were significantly longer with mivacurium than with atracurium (mean 25.2(SD 4.7) versus 22.6(3.1) min, p < 0.01). We found that the evidence that mivacurium has a slower recovery than the less potent atracurium may be true using the bilateral, isolated forearm technique and that the discrepancy might be due to a difference in the pharmacokinetic variables of the two drugs.
Kim
S Y
SY
Department of Anesthesiology, School of Medicine, Soon Chun Hyang University and Hospital, Seoul, Korea.
Hwang
K H
KH
Ok
S Y
SY
Kim
S I
SI
Kim
S C
SC
Park
W
W
D000328:Adult; D001279:Atracurium / Q000494:pharmacology*; D005542:Forearm / Q000502:physiology; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology*; D000077590:Mivacurium; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D013997:Time Factors; D014111:Tourniquets
D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D000077590:Mivacurium