Carfentanil is an analogue of the popular synthetic opioid analgesic fentanyl, and is one of the most potent opioids known (also the most potent opioid used commercially). Because of the lack of information provided, the emergency workers did not bring adequate supplies of naloxone (opioid inverse agonist) or naltrexone (opioid antagonist) to prevent complications in many of the victims and there were subsequently over 125 confirmed deaths from both respiratory failure and aerosol inhalation during the incident. Assuming that carfentanil and remifentanil were the only active constituents (which has not been verified by the Russian military), the primary acute toxic effect to the theatre victims would have been opioid-induced apnea; in this case mechanical ventilation and/or treatment with opioid antagonists would have been life-saving for many or all victims.
-O692.gif)