Potentiation of the neuromuscular blockade produced by alcuronium with halothane, enflurane and isoflurane.
The potentiation of alcuronium by halothane, enflurane and isoflurane was investigated using electromyography. In the first study, cumulative dose-response curves were constructed in four groups of 10 patients anaesthetized with one of the inhalation agents and nitrous oxide, or with fentanyl and droperidol (control). All three agents reduced the ED50 of alcuronium; the effect was marked with isoflurane (P less than 0.005) but less so with halothane (P less than 0.05) and enflurane (ns). In the second part of the investigation, designed primarily to test the duration of action of alcuronium with each agent, a single bolus dose of alcuronium 0.2 mg kg-1 was given to four similar groups (n = 5). The duration of action was significantly prolonged by enflurane (P less than 0.01) and isoflurane (P less than 0.05), but not by halothane. The possible reasons for this are discussed.
D000200:Action Potentials / Q000187:drug effects; D000443:Alcuronium / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004737:Enflurane / Q000494:pharmacology*; D005260:Female; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology*; D009132:Muscles / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects*; D013997:Time Factors; D014117:Toxiferine / Q000031:analogs & derivatives*
D004737:Enflurane; D014117:Toxiferine; D007530:Isoflurane; D000443:Alcuronium; D006221:Halothane