A comparative study of the dose-response and time course of action of rocuronium and vecuronium in anesthetized adult patients

• Published in: Journal of clinical anesthesia 1998-08, Vol.10 (5), p.410-415
• Main Authors: Xue, Fu S., Liao, Xu, Liu, Jian H., Tong, Si Y., Zhang, Yan M., Zhang, Ru J., An, Gang, Luo, Lai K.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Androstanols - administration & dosage; Anesthesia Recovery Period; Anesthesia, General; Anesthetics, Inhalation - administration & dosage; Anesthetics, Intravenous - administration & dosage; Dose-Response Relationship, Drug; Electric Stimulation; Female; Fentanyl - administration & dosage; Humans; Linear Models; Male; Middle Aged; Neuromuscular Blockade; Neuromuscular Nondepolarizing Agents - administration & dosage; Neuromuscular relaxants: rocuronium; neuromuscular relaxants: vecuronium; Nitrous Oxide - administration & dosage; Oxygen - administration & dosage; pharmacodynamics: dose-response; pharmacodynamics: time-course of recovery; Prospective Studies; Thiopental - administration & dosage; Time Factors; Ulnar Nerve - drug effects; Ulnar Nerve - physiology; Vecuronium Bromide - administration & dosage
• ISSN: 0952-8180; 1873-4529
• DOI: 10.1016/S0952-8180(98)00056-7

Study Objectives: (1) To compare the dose-response relations of rocuronium and vecuronium in healthy adult patients anesthetized with nitrous oxide-oxygen-fentanyl-thiopental; and (2) to evaluate the time-course of action of two drugs following equipotent doses. Design: Prospective, randomized, clinical comparison. Setting: Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College. Patients: 60 ASA physical status I patients, aged 17–51 years, scheduled for elective plastic surgery. Interventions: All patients were randomly assigned to either the rocuronium or vecuronium group. General anesthesia was induced with thiopental 4 to 6 mg/kg and fentanyl 2 to 4 μg/kg intravenously (IV), and maintained with 60% nitrous oxide (N 2O) in oxygen. Further increments of thiopental or fentanyl were given as required. The dose-response relations of rocuronium and vecuronium were determined by the cumulative dose-response technique. Measurements and Main Results: Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 seconds. The percentage depression of first twitch (T 1) was used as the study parameter. The cumulative dose-response curve of vecuronium was shifted to the left in a parallel fashion compared with that of rocuronium. As assessed by linear regression, the potency ratio of vecuronium:rocuronium was 1:7.2. There were significant differences in the ED 50, ED 90, and ED 95 between the two drugs. After IV administration of equipotent doses of both drugs (2 × ED 90), the duration of peak effect, clinical duration, recovery index, and total duration were not significantly different between the two drugs. Conclusions: Compared with vecuronium, rocuronium is a low-potency, nondepolarizing relaxant, and its neuromuscular blocking potency is approximately 15% that of vecuronium in adult patients anesthetized with N 2O and fentanyl. Following equipotent doses, the time-course of recovery for rocuronium is similar to that of vecuronium.