In cases of extreme overdose, which pharmaceutical agent would most likely be administered?

Naloxone hydrochloride, commonly known as Narcan, is an opioid antagonist primarily used to reverse the effects of opioid overdose. In cases of extreme overdose where there is a threat to the patient's life due to respiratory depression or coma caused by opioids, naloxone quickly restores normal respiration and increases alertness. Unlike other agents mentioned, which are anesthetic agents, naloxone targets the underlying cause of the overdose by blocking the opioid receptors in the brain.

In situations of opioid overdose, the administration of Naloxone can be life-saving, as it acts rapidly to displace opioids from their receptors, effectively reversing the overdose effects. Other agents listed are not indicated for opioid overdoses and do not provide the same immediate antidotal effect that naloxone does in this context.