RECOVERY OF ATRACURIUM AND VECURONIUM NEUROMUSCULAR BLOCK IN THE ISOLATED FOREARM

The duration of recovery from neuromuscular block after a 3 x ED90 dos e of atracurium or vecuronium is similar in spite of a three-fold diff erence in their elimination half-lives. We have investigated simultane ous spontaneous recovery from equipotent doses of atracurium and vecur onium in the isolated forearms of volunteers in order to attempt to ex plain this paradox. Simultaneous administration of the two drugs, one in each of the subjects forearms, allowed direct comparison of recover y to be made against the same plasma concentration of drug. The recove ry index of atracurium was found to be significantly longer than that of vecuronium. We suggest that this observation, when considered with the different plasma concentrations after a 3 x ED90 dose, helps to ex plain the similar duration of action of the two drugs during the recov ery phase after a large systemic bolus.