How Long Does Narcan Last? Effects and Interactions

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Jennifer Berger LCSW MSW

Clinical Director, Clinical Supervisor, EMDR Provider
I am a Licensed Clinical Social Worker and graduated with a degree from the USC School of Social Work in 2015 with an emphasis in mental health. I began my career working with the Orange County Welfare to Work Program providing mental health services to reduce barriers to employment. I have spent the last 5 years working various levels in behavioral health, providing direct service to those struggling with co-occurring disorders. Using an eclectic and integrative approach, I incorporate the AIP model with EMDR, Person-in-Environment (PIE), Motivational Interviewing (MI), Cognitive Behavioral Therapy (CBT), Dialectical Behavioral Therapy (DBT), family systems, interpersonal and solution-focused therapy along with Rogerian positive regard into my practice.

Since 2016, over 700,000 American lives have been lost due to opioid overdose deaths. Fortunately, the numbers continue to decrease each year, largely due to Narcan. 

Narcan is a life-saving intervention playing a key role in ending the opioid pandemic. In states that enacted laws that made it easier for the general public to access Narcan, there was an average 14% decrease in opioid-overdose deaths, according to a study from the Journal of Addictive Behaviors [1]. 

It’s important for those who work with the general public to understand what Narcan is, the role it plays in preventing overdose, and how long the effects last. 

What is An Opioid Antagonist? 

An opioid antagonist such as Narcan binds to opioid receptors in the central nervous system, but does not activate them. It blocks the receptors and prevents opioid agonists (e.g., fentanyl or morphine) from binding and producing effects. 

The main opioid receptors involved are the mu, kappa, and delta receptors. By occupying these receptors, the effects of opioid overdoses are reversed, such as respiratory depression or loss of consciousness [2]. 

Naloxone vs Naltrexone: What’s The Difference?

Naloxone and naltrexone often get mistaken for each other due to their similar-sounding name and association with opioid use disorder; however, they differ in their use and function. 

Naltrexone is an FDA-approved medication used in the long-term treatment of opioid use disorder, often as part of a Medication Assisted Treatment (MAT) program [2]. 

Drug Name NaloxoneNaltrexone 
Common Name/BrandNarcanVivitrol, ReVia, 
Administration Nasal spray, IV, or IM shot Pill, Capsule, Injectable 
UsesRapidly reverse opioid overdose Assists opioid addicts in long-term recovery, reduces cravings
How it Works Immediately displaces opioids from brain receptors Attaches to opioid receptors in the brain 
Length of Effects 30 to 90 minutes 1 pill works for approx 24 hours, injectable form can last up to 30 days 

Understanding Narcan’s Role in Overdose Reversal 

Narcan (Naloxone) is a life-saving medication used to quickly reverse opioid overdoses from drugs such as fentanyl, heroin, morphine, and prescription pain pills such as oxycodone and hydrocodone. It can be administered through a nasal spray (most common method), intravenously, or intramuscularly. 

Naloxone targets the same receptor sites as opioids such as fentanyl, heroin, and pain pills, but binds more strongly, displacing the opioids already attached and preventing them from working. It can quickly restore normal respiration in someone whose breathing has slowed or stopped due to overdose [3]. 

The Mechanism of Narcan 

Naloxone competitively displaces opioids from opioid receptors in the central nervous system. Its mechanism of action is centered on the role it plays as an opioid receptor antagonist, specifically at the mu, kappa, and delta opioid receptors. Narcan binds to these receptors in the brain to quickly block the effects of opioids 

When to Use Narcan

It’s important to administer Narcan if you notice signs of an overdose. Even if you are unsure the individual is overdosing on opioids, Narcan can still be used as a precaution and is safe to use even if there are no opioids in the body.  

Common signs of an opioid overdose and when to use Narcan include:

  • Slow, irregular, or stopped breathing 
  • Blue or purple lips or fingertips 
  • Pinpoint pupils 
  • Loss of consciousness 
  • Heavy limbs, lack of coordination 
  • Reduced heartbeat, low blood pressure 
  • Vomiting and disorientation 

How Long Does Narcan Last After Administration? 

Narcan works incredibly quickly, reversing effects in as little as two to five minutes. However, the effects are short-lasting (only 30 to 90 minutes). Narcan is used as a life-saving tool to increase the response time for emergency personnel to arrive. It is not a long-term treatment option for opioid use disorder.  

Narcan Side Effects: How Long Do They Last? 

Narcan can cause several uncomfortable side effects, although these only last for a few hours to a day at most. They often include:

  • Muscle pain
  • Diarrhea
  • Runny nose
  • Goosebumps
  • Anxiety
  • Nausea and vomiting 

Is Narcan A Controlled Substance?

Narcan is not a controlled substance. It is the only FDA-approved opioid antagonist for acute overdose reversal. It is sold over the counter in pharmacies or given out in Narcan distribution programs as a harm-reduction intervention. You do not need a prescription to buy Narcan, and there are no federal age restrictions, meaning those under 18 can purchase it if necessary. 

Narcan Shelf Life and Storage

The typical shelf life of Narcan is about 4 years if stored properly. The ideal storage is room temperature (59 to 77 degrees), away from light. If Narcan is exposed to extreme temperatures or sunlight, it can reduce its effectiveness. 

Expired Narcan can still be effective, but it is not guaranteed. It’s still recommended to use Narcan if it has expired, if you have no other option, as it won’t cause any adverse effects. 

Naloxone Interactions and Safety Considerations 

Narcan is generally safe and can be administered to children and teens. However, it can cause acute withdrawal symptoms in individuals with opioid use disorder due to sudden opioid displacement. 

It has little effect on people without opioids in their system and is safe to use even if alcohol is present. It’s important to monitor an individual who was just administered Narcan and wait for emergency medical attention to arrive. 

The Importance of Drug Addiction Treatment 

Narcan helps stop immediate tragedies, but drug addiction treatment is essential for long-term recovery. 

Residential treatment (inpatient rehab) is a structured, safe environment with 24/7 support to provide medically supervised detox and personalized mental health treatment. Throughout residential treatment, individuals participate in therapy, peer support groups, family therapy, and holistic healing activities such as yoga, mindfulness, and creative arts. 

Aftercare and transitional support also play a key role in sustainable healing. This focuses on preventing relapse by helping patients connect with ongoing services such as outpatient therapy, secure housing, or employment. 

Drug Rehab in Southern California

For more than 30 years, Northbound Treatment Services in California has been at the forefront of providing lifesaving, compassionate residential care and specialized services to help people from all walks of life feel better, discover themselves, and live free from addiction. We have facilities throughout California. Reach out to our admissions team now. 

Our admissions team is available 24/7. Contact us now

Sources

[1] McLeellan, C. et al. 2018. Opioid-overdose laws association with opioid use and overdose mortality. Journal of Addictive Behaviors. 

[2] Theriot, J. et al. 2023. Opioid Antagonists. National Library of Medicine. 

[3] Berger, E. 2023. Naloxone has been hailed as life-saving. Why isn’t it given to those who need it?

Author

  • Jennifer Berger LCSW MSW

    Clinical Director, Clinical Supervisor, EMDR Provider

    I am a Licensed Clinical Social Worker and graduated with a degree from the USC School of Social Work in 2015 with an emphasis in mental health. I began my career working with the Orange County Welfare to Work Program providing mental health services to reduce barriers to employment. I have spent the last 5 years working various levels in behavioral health, providing direct service to those struggling with co-occurring disorders. Using an eclectic and integrative approach, I incorporate the AIP model with EMDR, Person-in-Environment (PIE), Motivational Interviewing (MI), Cognitive Behavioral Therapy (CBT), Dialectical Behavioral Therapy (DBT), family systems, interpersonal and solution-focused therapy along with Rogerian positive regard into my practice.

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