Open AccessAnesthetic Interaction Between Midazolam and Halothane in Humans
Author(s) -
Yoshimi Inagaki,
Koji Sumikawa,
Ikuto Yoshiya
Publication year - 1993
Publication title -
anesthesia and analgesia/anesthesia and analgesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.404
H-Index - 201
eISSN - 1526-7598
pISSN - 0003-2999
DOI - 10.1213/00000539-199303000-00029
Subject(s) - midazolam , halothane , medicine , anesthetic , anesthesia , minimum alveolar concentration , bolus (digestion) , surgery , sedation
The present study was undertaken in humans to determine the anesthetic efficacy of midazolam in terms of its ability to reduce halothane minimum alveolar anesthetic concentration (MAC). Fifty women scheduled for simple or radical hysterectomy were allocated randomly to one of four groups; group A was given no midazolam as a control; groups B, C, and D were given midazolam intravenously by a bolus of 0.1, 0.2, and 0.4 mg/kg followed by infusion of 1, 2, and 4 micrograms.kg-1 x min-1, respectively. Halothane MAC was 0.78%, 0.47%, 0.38%, and 0.23% at mean serum midazolam concentrations of 0, 134, 250, and 539 ng/mL in groups A, B, C, and D, respectively. The interaction between halothane and midazolam in the anesthetic efficacy conformed to an exponential fit. The results indicate that midazolam produces marked reduction of halothane MAC in humans at serum concentrations lower than that required to cause sleep. Lastly, midazolam's potentiation of halothane has a saturated nature.