## How it works
Opioids like heroin, fentanyl, oxycodone, and methadone bind to mu-opioid receptors in the brain. At high doses they suppress the brainstem circuits that drive breathing — this respiratory depression, not the sedation itself, is what kills people.
Naloxone is a **competitive opioid antagonist** with very high affinity for those same receptors. It physically knocks the opioid molecules off the receptor and occupies the site without activating it. Within 2–5 minutes (intranasal) or 2–3 minutes (intramuscular), breathing typically resumes.
Two important limits:
- **It's temporary.** Naloxone's effect lasts roughly 30–90 minutes. Many opioids outlast it — especially methadone, extended-release formulations, and large fentanyl doses stored in body fat. Someone can wake up and then stop breathing again ("re-narcotization"). This is the single biggest reason emergency services are still needed.
- **It only works on opioids.** It does nothing for benzodiazepines, alcohol, stimulants, or xylazine. But because most overdoses involve mixed substances and opioids are usually in the mix, giving it is still the right call.
## When to use it
Give naloxone if someone is **unresponsive and breathing abnormally**. Key signs:
- Won't wake to shouting or a firm sternal rub
- Breathing that is absent, very slow (under ~10 breaths/min), shallow, or making gurgling/snoring/choking sounds
- Blue or gray lips, fingertips, or face (may look ashen or pale on darker skin)
- Limp body, pinpoint pupils
**When in doubt, give it.** Naloxone has essentially no effect on someone who hasn't taken opioids, so the cost of being wrong is near zero. Don't wait for confirmation of drug use.
## What to do
1. **Try to rouse them** — shout their name, rub knuckles hard on the breastbone.
2. **Call emergency services** (911 in the US). Say the person isn't breathing.
3. **Give naloxone** — nasal spray: full device into one nostril, press plunger. Injectable: into the outer thigh muscle, through clothing if needed.
4. **Support breathing** — rescue breaths (one every 5 seconds) if you're trained and willing; chest compressions if there's no pulse.
5. **Repeat after 2–3 minutes** if there's no improvement. Multiple doses are often needed with fentanyl. Use the other nostril for a second spray.
6. **Stay with them** until help arrives. If they're breathing but not alert, put them on their side (recovery position) to prevent choking on vomit.
## A few practical notes
- **Precipitated withdrawal** is common after reversal — vomiting, sweating, agitation, sometimes anger or confusion. It's miserable but not dangerous. The goal is restoring breathing, not full alertness, so don't stack doses trying to make someone fully lucid.
- People sometimes want to leave or use again immediately. Using again while naloxone is active can lead to a second overdose once it wears off.
- **Good Samaritan laws** in most US states and many other jurisdictions protect bystanders who call for help during an overdose from drug possession charges. Specifics vary.
- Naloxone is available over the counter in US pharmacies as Narcan nasal spray, and free through many harm-reduction programs, health departments, and libraries.
If you're likely to be around opioid use — personally, professionally, or through family — carrying it and doing a short training (many are 20 minutes, free, online or in person) is worth it.