Nalmefene Vs. Naloxone: Making the Right Choice

Nalmefene and naloxone are opioid-blocking medications used to reverse the effects of an opioid overdose. Naloxone, commonly known as Narcan, works immediately, but the effects are short-lived, making it ideal for emergency response situations. Nalmefene nasal spray, known as Opvee, acts for a longer duration of up to eight hours, offering extended protection against potent opioids such as fentanyl. Both medications save lives, but as of now, Narcan is preferred to reduce the risk of an opioid overdose.¹

ChoicePoint offers insurance-covered opioid addiction treatment along with Naloxone and Nalmefene prescriptions to save lives from opioid overdose. Call 844.445.2565 for personalized assistance. 

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What is the Difference Between Nalmefene (Opvee) and Naloxone (Narcan)?

Nalmefene and Naloxone may be used for the same purpose but have different active ingredients and are used in slightly different ways. Nalmefene is available as:

• Opvee Nasal Spray (prescription only) to reverse opioid overdose 
• Nalmefene tablets (Revex) for alcohol addiction treatment. 

Whereas Naloxone (Narcan) is an over-the-counter nasal spray that can be carried and used by anyone. Naloxone can be administered when a person is displaying early signs of opioid overdose or to reverse an opioid overdose. 

The key features and differences are summarized below: 

Nalmefene Vs. Naloxone Mechanism of Action

Both naloxone and Nalmefene are opioid antagonists, which means they block the effects of opioids in the brain. Nalmefene binds to opioid receptors with the highest affinity for mu (μ)-opioid receptors. By doing so, it reverses the effects of opioids such as respiratory depression and euphoria. For AUD treatment, it modulates the brain’s reward pathways to reduce alcohol cravings. ⁴

Naloxone works similarly. It displaces opioids immediately from opioid receptors, restoring normal breathing and reversing respiratory depression.

a. Onset of Action and Duration of Narcan Vs. Opvee 

Nalmefene acts within 5-15 minutes. Its duration of action is also much longer, 8-12 hours, making it suitable for sustained reversal or treatment maintenance. Whereas Naloxone has a much quicker onset of action within 2-5 minutes, making it a preferred choice for emergency uses. However, Naloxone effects last only for 30-90 minutes and stay in the system for a shorter duration, which means repeated dosing is required, especially with long-acting opioids.

b. Nalmefene (Opvee) Vs. Naloxone (Narcan) Side Effects

Some side effects include: 5

c. Addictive Potential: Can You Get Addiction to Narcan or Nalmefene?

Both Nalmefene (Opvee) and Naloxone (Narcan) are non-addictive opioid antagonists. Nalmefene or Narcan can not get you high. They do not produce euphoria, sedation, or any pleasurable effects commonly linked to opioids. Their primary role is to reverse or block the effects of opioids at receptor sites in the brain.

How To Decide Between Opvee Vs. Narcan?

Choosing between Opvee (Nalmefene) and Narcan (Naloxone) depends on the situation, medical context, and individual needs during opioid overdose response or recovery support. If an immediate overdose reversal is needed, Narcan is the most widely used and trusted option. It works quickly, is easily accessible, and is approved for both home and clinical use. Most first responders and harm reduction programs are trained to administer Narcan.

Opvee provides longer protection, but it is a prescription-only spray and not everyone may have the training to administer it. Still, your healthcare provider may recommend the best medication after reviewing your history and medical needs.

Administering Naloxone and Nalmefene Safely

Nalmefene vs Naloxone for Alcohol Dependence: Which is Better?

Nalmefene has shown clinical effectiveness in reducing alcohol consumption and cravings, whereas Naloxone is not approved or widely used for alcohol dependence treatment.

Nalmefene works as an opioid receptor modulator, primarily blocking the brain’s reward response to alcohol, thereby reducing the desire to drink. Though Nalmefene is not FDA-approved for alcohol dependence in the U.S, Studies published show that individuals taking Nalmefene experienced significant reductions in heavy drinking days and total alcohol intake compared to placebo groups. ⁶

Nalmefene Vs. Naloxone For Opioid Dependence: Making the Right Choice

For opioid overdose reversal, Narcan is preferred over Naloxone. Here is an overview of the pros and cons of Opvee Vs. Narcan for better understanding:

Helpful Read: Where can you get Naloxone in NJ?

Narcan or Opvee Administration: What is Next?

While Narcan (naloxone) and Opvee (nalmefene) are critical tools for reversing opioid overdoses, they are not long-term solutions. These medications can save lives by temporarily reversing respiratory depression, but they do not address the underlying opioid use disorder. Without follow-up treatment, individuals remain at high risk for relapse and future overdose.

Only comprehensive care can help you fully recover and sober up fast. Some options to consider are:

ChoicePoint Opioid Overdose Prevention and Addiction Treatment Program in NJ

ChoicePoint offers a comprehensive opioid addiction treatment program and opioid detox in Fair Lawn, NJ, designed to help individuals overcome opioid addiction. Our licensed addiction specialists in NJ provide Medication-Assisted Treatment (MAT), behavioral therapy, and personalized recovery plans that address both the physical and psychological aspects of addiction.

Highlights of our opioid addiction treatment program:

• 24/7 online Suboxone Doctors
• 24/7 online Subutex doctors
• Online Naltrexone prescriptions and clinic
• Online MAT Clinic
• Same-day prescription for suboxone
• Same-day Subutex prescription
• Accepting new patients for Suboxone and Subutex treatment
• Outpatient Suboxone treatment
• Outpatient Subutex treatment 
• Opioid withdrawal management
• Relapse prevention

If you are looking for online opioid addiction doctors to get online medication prescriptions, we have got you covered! Verify your insurance online or call 844.445.2565 to get started today.

Free Addiction Assessment

Please note this assessment is an initial self-screening, and it is not meant to be a medical assessment or clinical diagnosis of addiction. For proper diagnosis and treatment, schedule an appointment with ChoicePoint.

FAQs Related to Nalmefene Vs. Naloxone

More of your questions are answered below:

1. What is Another Name for Nalmefene?

Other names of Nalmefene are:

• Opvee (nasal spray)
• Revex (injectable formulation)
• Zurnai (Auto-injector)

2. What are the Three Types of Naloxone?

Three types are:

1. Nasal spray
2. Intravenous injection
3. Intramuscular injection

3. What is Nalmefene Used For?

Nalmefene nasal spray is an FDA-approved formulation to reverse opioid overdose.

References

1. Stolbach, A. I., Mazer-Amirshahi, M., Amirshahi, P. D., M., Nelson, L. S., & Cole, J. B. (2023, September 28). ACMT & AACT joint position statement: Nalmefene should not replace naloxone as the primary opioid antidote at this time—American College of Medical Toxicology & American Academy of Clinical Toxicology.
   https://www.acmt.net/wp-content/uploads/2023/12/ACMT-AACT-Joint-PS_Nalmefene.pdf
2. Nallani, S. C., Li, Z., Florian, J., Xu, Y., Sabarinath, S., Brescia-Oddo, T., Roca, R. A., Uppoor, R. S., & Mehta, M. U. (2025). FDA Approval Summary: Nalmefene Nasal Spray for the Emergency Treatment of Known or Suspected Opioid Overdose. Clinical pharmacology and therapeutics, 117(3), 620–626.
   https://doi.org/10.1002/cpt.3514
3. U.S. Food and Drug Administration. (2023, March 29). FDA approves first over-the-counter naloxone nasal spray [Press release]. Retrieved from
   https://www.fda.gov/news-events/press-announcements/fda-approves-first-over-counter-naloxone-nasal-spray
4. DrugBank Online. (2024). Nalmefene (DB06230). Retrieved from
   https://go.drugbank.com/drugs/DB06230
5. Indivior Inc. (2025, March). Signs and symptoms – OPVEE® Nasal Spray (for known or suspected opioid overdose). Retrieved from
   https://opvee.com/hcp/hcp-signs-symptoms/
6. Naudet, F., Palpacuer, C., Boussageon, R., & Laviolle, B. (2016). Evaluation in alcohol use disorders – insights from the nalmefene experience. BMC medicine, 14(1), 119.
   https://doi.org/10.1186/s12916-016-0664-9