title: The onset time of rocuronium is slowed by esmolol and accelerated by ephedrine.
abstract: Administration of ephedrine prior to rocuronium decreases the onset time of neuromuscular blockade from rocuronium by 26%. This effect was attributed to a increased cardiac output. If so, beta adrenergic-blocking drugs, which decrease cardiac output, should prolong the onset time of rocuronium. In a double-blind study, 60 patients were randomly assigned to three groups (n = 20) to receive either 70 microg. kg(-1) of ephedrine, 0.5 mg. kg(-1) esmolol or placebo, 30 s before induction of anesthesia. Onset time of rocuronium was defined as the time from the end of its injection to disappearance of all four twitches of the train-of-four. The onset time of rocuronium was significantly shorter after ephedrine (22%) and longer after esmolol (26%), as compared to placebo. No differences were observed among the three groups with regard to heart rate, systolic, diastolic or mean blood pressure. We concluded that a dose of 0.5 mg. kg(-1) of esmolol significantly prolongs the onset time of rocuronium with minimal hemodynamic changes.
authors.affiliation: Department of Anesthesiology, University of Texas Medical School at Houston, 77030, USA. pszmuk@anes1.med.uth.tmc.edu
authors.forename: P
authors.initials: P
authors.lastname: Szmuk
authors.forename: T
authors.initials: T
authors.lastname: Ezri
authors.forename: J E
authors.initials: JE
authors.lastname: Chelly
authors.forename: J
authors.initials: J
authors.lastname: Katz
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D000732:Androstanols; D001794:Blood Pressure / Q000187:drug effects; D004809:Ephedrine / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents; D011412:Propanolamines / Q000494:pharmacology*; D000077123:Rocuronium; D013997:Time Factors
chemical_list: D000319:Adrenergic beta-Antagonists; D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D011412:Propanolamines; D004809:Ephedrine; C036604:esmolol; D000077123:Rocuronium