What is the antidote for opioid overdose?

Naloxone is the antidote used for opioid overdose because it is an opioid antagonist that works by competitively binding to the same receptors in the brain that opioids do. This action effectively reverses the effects of opioids, such as respiratory depression, sedation, and hypotension, by displacing the opioid molecules from the receptors and blocking their action. Naloxone can rapidly restore normal breathing and consciousness in someone who is experiencing an opioid overdose, making it a crucial intervention in emergency medicine.

The other options do not serve as effective antidotes for opioid overdose. Flumazenil is a benzodiazepine antagonist and would be used to reverse benzodiazepine effects, not opioids. Atropine is an anticholinergic agent typically used for bradycardia or to dry secretions, playing no role in opioid toxicity. Activated charcoal may be used in cases of poisoning or overdose to adsorb certain substances if administered soon after ingestion, but it does not reverse the effects of opioids. Therefore, naloxone is the go-to antidote in cases of opioid overdose.