Midazolam acts synergistically with fentanyl for induction of anaesthesia
Ben-Shlomo, I.; abd-el-Khalim, H.; Ezry, J.; Zohar, S.; Tverskoy, M.
British Journal of Anaesthesia 64(1): 45-47
1990
ISSN/ISBN: 0007-0912 PMID: 2302375 Document Number: 361063
The induction dose-response of midazolam was compared with the dose-response of its combination with fentanyl and with that of fentanyl alone in three groups of 60 unpremedicated, ASA physical status I or II women undergoing minor gynaecological surgery. The end-point of induction of anaesthesia was inability to open eyes upon command. Dose-response curves were determined for each group with a probit procedure and compared with an isobolographic analysis. Midazolam was found to act in synergism with fentanyl for induction of anaesthesia. Twenty-five percent of the ED50 of fentanyl was required in combination with 23% of the ED50 for midazolam to achieve the ED50 of the combination. This degree of synergism may explain mutual potentiation between opioids and benzodiazepines reported previously.