Dose-response and time course of effect of rocuronium in male and female anesthetized patients.
To determine differences from dose-response and time-course of rocuronium between male and female patients, 60 adult patients (30 male and 30 female), ASA grade I, aged 17-52 yr, undergoing elective plastic surgery were studied. Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 s, and the percentage depression of the T1 response was used as the study variable. The dose-response relationship of rocuronium was determined by a cumulative dose-response technique. The results showed that the dose-response curve of rocuronium in the men was shifted to the right, indicating a decrease in the sensitivity to rocuronium-induced neuromuscular block versus the women. The 50%, 90%, and 95% effective doses of rocuronium were 178.4 +/- 53.7, 358.7 +/- 101.3, and 386.2 +/- 113.4 microg/kg, respectively, in male patients, and 128.8 +/- 42.5, 252.8 +/- 51.7, and 274.4 +/- 59.4 microg/kg in female patients. After an intravenous administration of total dose of 400 microg/kg rocuronium, neuromuscular block was significantly longer in the men than in the women. The duration of peak effect, clinical duration, and total duration were 6.5 +/- 3.0, 12.5 +/- 4.9, and 33.6 +/- 8.7 min, respectively, in male patients, and 11.8 +/- 2.7, 18.5 +/- 5.3, and 46.8 +/- 9.6 min in female patients. We conclude that women were approximately 30% more sensitive to rocuronium compared with men.


CONCLUSIONS
The authors found that women were 30% more sensitive to rocuronium than men. This suggests that the routine dose of rocuronium should be reduced in women compared with men.
Xue
F S
FS
Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
Tong
S Y
SY
Liao
X
X
Liu
J H
JH
An
G
G
Luo
L K
LK
D000293:Adolescent; D000328:Adult; D000732:Androstanols / Q000008:administration & dosage* / Q000494:pharmacology; D000758:Anesthesia; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage* / Q000494:pharmacology; D000077123:Rocuronium; D012727:Sex Characteristics
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium