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Naloxone Vs Naltrexone

Naloxone (Narcan) and naltrexone share similar medical applications, but play different roles in the process of opioid overdose recovery.

Naloxone provides life-saving aid to someone experiencing an opioid overdose, while naltrexone helps individuals overcome opioid dependence through long-term use.

What Is The Difference Between Naloxone And Naltrexone?

Placed side by side, the most distinctive difference between naltrexone vs naloxone is timing.

Naloxone (Narcan) takes effect immediately and wears off quickly, while naltrexone affects the body at a slower rate with a longer-lasting action upon the body.

Naloxone (Narcan)

Naloxone is a vital substance to treat individuals suffering from opioid overdose

The symptoms associated with opioid overdose are always serious, and often fatal. Fortunately, naloxone is one substance with the unique ability to reverse the symptoms of opioid overdose.

There are three main types of receptors in the brain that opioids activate. An overdose occurs when these brain receptors become overloaded with too much of a substance.

When administered, naloxone (Narcan) acts on the same three kinds of receptors that opioids do. Narcan both prevents opioids from binding to their corresponding receptors and “knocks off” those that are already attached.

One of the most dangerous symptoms of opioid overdose is the way it slows breathing to dangerously low levels. By blocking the connection between the opioid and receptor, naloxone effectively reverses the symptoms of overdose.

How Long Does Naloxone Block Opioid Receptors?

The fact that naloxone can reverse overdose so quickly makes it a vital substance to treat individuals suffering from opioid overdose. Naloxone takes effect within 5 minutes of administration and wears off after about 90 minutes.

It is important to note that since naloxone (Narcan) wears off so quickly, a person receiving Narcan will need professional medical attention as soon as overdose symptoms have passed. Failing to seek follow-up care may result in extreme withdrawals followed by intense cravings for opioids in short order.

What Are Common Administration Routes For Naloxone?

Naloxone is most commonly taken nasally, but injectable solutions allow individuals to administer the substance even without medical training.

Some studies have proposed extending its use to addressing septic shock, which is characterized by extremely low blood pressure as well as organ failure. The efficacy of the drug in this application is still inconclusive, however. Thus, opioid overdose remains naloxone’s only medically recognized treatment.

Is Naloxone Addictive?

As a stand-alone substance, naloxone does not have any potential for abuse. Naxolene’s primary function is to simply counter the effects of another drug, so it does not act upon the brain in any way that would encourage addiction.


Naltrexone is incredibly valuable for individuals who are overcoming a dependence to an opioid.

While naloxone (Narcan) is an emergency medication, naltrexone helps individuals overcome opioid addiction over a longer period of time. Naltrexone has a similar, but less forceful effect on the brain compared to naloxone.

While naloxone blocks all three of the brain’s opioid receptors, naltrexone blocks only one. Naltrexone targets the euphoria-inducing effect of opioids as a way to prevent dependence.

Naltrexone is incredibly valuable for individuals who are overcoming a dependence because it stifles the intoxicating feeling people seek to attain through opioid use.

After a period of detoxification, individuals who take naltrexone are able to focus on recovery without experiencing opioid cravings that can lead to relapse.

How Long Does It Take Naltrexone To Work?

Naltrexone can be taken either as a pill or as an injection, but effect of the substance lasts much longer when injected:

  • When taken orally, half of the dose will be eliminated from the body within four(4) hours whereas,
  • When injected the half-life extends to about seven (7) days.

The injection is more potent and effective, but the convenience of pills makes administration less complicated as this individuals to self-administer a pill daily.

In addition to opioid addiction treatment, naltrexone has also shown promise as a method to combat alcohol dependence. Though the two substances might seem very different, alcohol and opioids impact some of the same receptors in the brain.

Is Naltrexone Addictive?

Naltrexone is highly unlikely to be habit-forming, and, therefore, has little risk for abuse.

Side effects are rare and mostly related to withdrawals from substance abuse rather than naltrexone itself. These effects may include:

  • Nausea
  • Headache
  • Body Aches
  • Loss of Appetite
  • Depression
  • Dizziness
  • Tiredness
  • Trouble Sleeping
  • Anxiety
  • Drowsiness

Naltrexone is most effective when administered by a medical professional. Access to powerful treatments like this as part of a holistic recovery program can not only save a life from opioid overdose, but help them rebuild a new one drug-free.

Naltrexone vs Naloxone: How Do I Find Out More?

Though they share strikingly similar names, each substance has unique applications. Naloxone is an appropriate first step in assisting someone who has overdosed on opiates, but further treatment is needed to prevent overdose from happening again.

If you know someone struggling with an opioid addiction, finding a reliable medication assisted treatment (MAT) center can be a challenge. At Reflections, we provide a ‘whole-patient’ approach to the treatment of substance use disorder.

Reach out to us today to talk to our highly qualified team about how they use all resources available to provide individualized care for each patient.