Editing Non-lethal weapon (section)

===Sleep gas===
During the 2002 [[Moscow theater hostage crisis]], Russian special forces used an unidentified gas (thought to be [[3-methylfentanyl]] or another [[fentanyl]] variant dissolved in halothane gas) in an attempt to induce sleep in both hostages and terrorists. Many of the hostages and terrorists (including all of the suicide bombers) were anesthetized, but some terrorists donned gas masks and thus were able to avoid the effects of the gas. Because the agent used was a potent Fentanyl derivative (a synthetic opioid), it causes respiratory depression and ultimately respiratory failure if administered in high enough dosages. The central nervous system effects, such as anesthesia and respiratory depression could have been reversed by an opioid antagonist such as [[naloxone]], which is stocked by hospitals and most ambulances. However, because the Russian authorities did not release any information regarding what type of agent was used, medical professionals were unaware that an opioid had been used during the rescue attempt and thus were unable to administer the antidote which could have saved most hostages. Approximately 700 hostages were rescued, while 130 died from exposure to the gas. All the terrorists were ultimately killed by Russian forces through some combination of gas exposure and gunfire.{{citation needed|date=April 2022}}