Phenytoin-induced resistance to vecuronium.
Chronic phenytoin therapy causes resistance to some nondepolarising muscle relaxants. We have confirmed that this resistance is seen with vecuronium and suggest that at least a week of phenytoin therapy is required for a significant effect to develop. The mechanism of this resistance is not known. We have shown that an exaggerated rise in serum potassium after succinylcholine does not occur in patients with demonstrated resistance to vecuronium from chronic phenytoin therapy. This would suggest that significant extrajunctional acetylcholine receptor proliferation is an unlikely mechanism.
Platt
P R
PR
Department of Anaesthesia, Sir Charles Gairdner Hospital, Perth, Western Australia.
Thackray
N M
NM
D000762:Anesthesia Recovery Period; D004347:Drug Interactions; D004351:Drug Resistance; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D009493:Neurosurgery; D010672:Phenytoin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D011188:Potassium / Q000097:blood; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000502:physiology; D012044:Regression Analysis; D013390:Succinylcholine / Q000494:pharmacology; D013997:Time Factors; D014673:Vecuronium Bromide / Q000008:administration & dosage / Q000494:pharmacology*
D011950:Receptors, Cholinergic; D010672:Phenytoin; D014673:Vecuronium Bromide; D013390:Succinylcholine; D011188:Potassium