Neuromuscular interactions between succinylcholine and esmolol in the rat.
To study the neuromuscular interactions between succinylcholine (Sch) and esmolol, we determined the dose-response relationship of Sch and the neuromuscular actions of the 3xED90 dose of Sch, both prior to and following esmolol pretreatment. Twenty rats were anaesthetized with urethane. Train-of-four stimulation was applied every 12 s to the sciatic nerve, and the electromyogram (EMG) of the tibialis anterior muscle was measured. The results showed that the potency of Sch decreased with esmolol pretreatment. The ED50 of Sch increased significantly, from 191 ug/kg to 227 ug/kg after esmolol infusion, p < 0.05. The duration of EMG depression achieved by the 3xED90 dose of Sch decreased significantly with esmolol pretreatment (12 min vs 14 min p < 0.05), and also the onset time was significantly longer (43 sec vs 28 sec, p < 0.05). There were no significant difference between groups with regard to the maximal block or recovery index. The results of two methods of study demonstrated that the pharmacological interaction between Sch and esmolol is antagonistic instead of potentiating.
Chang
R Y
RY
Department of Anesthesiology, Taipei Municipal Yang-Ming Hospital, Taiwan, R.O.C.
Chern
S C
SC
Chiang
Y Y
YY
Liou
M D
MD
Tseng
K F
KF
Tsai
S K
SK
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D004347:Drug Interactions; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects*; D011412:Propanolamines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects*; D013390:Succinylcholine / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D013390:Succinylcholine; C036604:esmolol