Korean J Anesthesiol.  2003 Nov;45(5):650-655. 10.4097/kjae.2003.45.5.650.

Effects of Ondansetron on the Neuromuscular Block of Vecuronium, Rocuronium or Atracurium in a Rat Phrenic Nerve-Hemidiaphragm Preparation

• Ok SY
• Kim SC
• Kim SI
• Lee JS
• Jung JY
• Hwang KH
• Kim SY

• KMID: 1935957
• DOI: http://doi.org/10.4097/kjae.2003.45.5.650

Abstract

BACKGROUND: Ondansetron, a 5-HT3 receptor antagonist, is widely used for the prevention of postoperative nausea and vomiting. However, the interaction of ondansetron with non-depolarizing muscle relaxants have not been reported until now. Therefore we studied the effects of ondansetron on the neuromuscular block of vecuronium, rocuronium or atracurium in vitro.
METHODS
A square wave 0.1 Hz supramaximal stimuli was applied to the phrenic nerve-hemidiaphragm preparation of a rat, and the twitch height response was recorded mechanomyographically. We measured cumulative concentration response curves of vecuronium, rocuronium or atracurium alone and after pretreating with ondansetron (1microgram/ml). We also measured the effects of ondansetron. The EC50's and EC90's of these muscle relaxants alone and after pretreatment with ondansetron were calculated using an inhibitory sigmoid Emax model.
RESULTS
Ondansetron depressed the twitch height in a dose-dependent manner, and its potency was lower than the muscle relaxants. The EC50 and EC90 of ondansetron were 14.7microgram/ml and 33.4microgram/ml, respectively. Pretreated ondansetron (1microgram/ml) significantly reduced the EC50's and EC90's of vecuronium, rocuronium and atracurium (P<0.05).
CONCLUSIONS
Ondansetron itself may have neuromuscular blocking properties, and it significantly enhances the neuromuscular blocks induced by vecuronium, rocuronium or atracurium.

Keyword

atracurium; neuromuscular transmission; ondansetron; rocuronium; vecuronium

MeSH Terms

Animals
Atracurium*
Colon, Sigmoid
Neuromuscular Blockade*
Neuromuscular Nondepolarizing Agents
Ondansetron*
Postoperative Nausea and Vomiting
Rats*
Receptors, Serotonin, 5-HT3
Vecuronium Bromide*
Atracurium
Neuromuscular Nondepolarizing Agents
Ondansetron
Receptors, Serotonin, 5-HT3
Vecuronium Bromide