Naloxone vs Naltrexone

Naloxone vs naltrexone: emergency overdose reversal versus longer-acting craving-blocking medicine for alcohol or opioid use disorder.

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Key takeaway

Naloxone (Narcan) reverses opioid overdose in minutes. Naltrexone blocks opioid effects and supports alcohol recovery as a prescribed medicine. They are not interchangeable. Call or text (800) 653-9376 if you need help matching the right tool.

Last updated: Wed Oct 07 2026 00:00:00 GMT+0000 (Coordinated Universal Time)

The names sound alike. The jobs do not.

Call 911 and give naloxone for suspected opioid overdose. Call or text 988 for a crisis.

Naloxone (Narcan and generics)

Naloxone temporarily knocks opioids off receptors to restore breathing. It is carried by first responders, sold over the counter in many pharmacies, and distributed by harm-reduction programs. Effects wear off; stay with the person and seek emergency care.

Naltrexone

Naltrexone is a prescribed antagonist used for alcohol use disorder and, after complete opioid detox, for opioid use disorder (oral or extended-release injectable). It is not an emergency rescue spray.

Side-by-side essentials

Emergency rescue: naloxone
Ongoing treatment medicine: naltrexone (when clinically appropriate)
Opioid agonist treatments: buprenorphine and methadone (different pathway)

Broker filter

A salesperson who confuses Narcan with Vivitrol is not qualified to plan your medication care.

Next step

Get naloxone into the house today. For naltrexone or other MOUD questions, call or text (800) 653-9376.

Additional Resources

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Common Questions

Is naloxone the same as naltrexone?

No. Naloxone is an emergency overdose reversal medicine. Naltrexone is a prescribed treatment medicine for opioid or alcohol use disorder.

When do I use naloxone?

When someone may be overdosing on opioids: slow breathing, unresponsiveness, blue lips. Call 911 and give naloxone.

What is naltrexone used for?

Oral or injectable naltrexone (including Vivitrol) can reduce alcohol craving and block opioid receptors after full detox from opioids.

Can I take naltrexone if I still use opioids?

Starting naltrexone too soon after opioids can precipitate withdrawal. Clinicians time induction carefully.

Where can I get help choosing?

Call or text (800) 653-9376 for treatment matching, or ask a clinician. Keep naloxone at home either way.