Naloxone is the antidote for opioid overdose. It works by quickly blocking opioid receptors and reversing dangerous effects such as slowed breathing and loss of consciousness.
What naloxone reverses
You use naloxone when you suspect an opioid overdose, including overdose from heroin, fentanyl, oxycodone, morphine, methadone, or similar opioids. It is not an antidote for alcohol, benzodiazepines, or most other drug overdoses.
How it works
Naloxone is an opioid receptor antagonist, meaning it binds to opioid receptors and displaces the opioid already attached there. That action helps restore breathing, which is the main life-threatening problem in opioid overdose.
When to use it
Use naloxone immediately if a person has signs of opioid overdose such as very slow or stopped breathing, pinpoint pupils, blue or gray lips, or cannot be awakened. Because naloxone’s effect may wear off before the opioid does, you still need emergency medical help right away.
Practical points
Naloxone is available in several forms, including nasal spray and injectable forms, and it can be given by bystanders, first responders, and healthcare workers. If the person does not respond after a dose, you may need to give another dose and continue rescue breathing until help arrives.