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Narcan Nasal Spray for Opiate Overdose Reversal

Written by Jonathan Strum

& Medically Reviewed by Dr. Bonnie Bullock, PHD

Medically Reviewed

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This article was reviewed by a medical professional to guarantee the delivery of accurate and up-to- date information. View our research policy.

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Last Updated - 12/28/2022

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Updated 12/28/2022

Key Takeaways

  • Narcan can reverse an opioid overdose and save lives
  • Narcan will only work on the opioid class of drugs and will not reverse overdoses from other drugs (e.g., alcohol or cocaine)
  • Anyone can buy and administer Narcan nasal spray for suspected or known opioid overdoses
  • Narcan is not a cure for opioid addiction.
  • Additional treatment besides Narcan  is necessary after an overdose

Have you heard of Narcan? If an opioid overdose of a loved one or stranger is suspected, having Narcan nasal spray on hand can save a person’s life. Learn about how Narcan nasal spray can be used for opioid overdose reversal.

When someone is suspected to be experiencing an opioid overdose, administering the opioid overdose reversal drug Narcan may save a person’s life. During an overdose situation, the first step is to call 911 or emergency services. Once they arrive, emergency medical personnel may administer Narcan nasal spray. However, anyone can easily administer this drug. Therefore, if a loved one has overdosed before, it may be wise to have Narcan on hand in the event of another overdose. Narcan can be purchased from any major drugstore in the United States without a prescription. If cost is an issue, Narcan is covered by most insurance companies.

What Is Narcan?

First, what is Narcan nasal spray? Narcan is a brand-name of a generic drug known as naloxone HCl. The main use of Narcan is as an emergency medicine for treating either known or suspected opioid overdoses. Narcan directly counteracts the dangerous and life-threatening effects of opioid use.

Narcan FDA Approval

Before going on the market, Narcan had to first be approved by the United States Food and Drug Administration (FDA) for its safety and efficacy at reversing opioid overdose. When was Narcan FDA-approved? Nasal Narcan was approved for immediate release on November 18, 2015.

How Does Narcan Work?

How does Narcan work, and what is Narcan used for? Narcan is an antagonist of opioid receptors that are found in the brain, nervous and digestive systems. In general, antagonists reverse and block the effects of opioids by directly competing against opioids that bind to opioid receptors.

Upon being sprayed into the nasal cavity of an individual who is overdosing from opioid use, Narcan rapidly begins working. Heavy opioid use causes decreased or stopped breathing, and Narcan restores these to normal levels and can save people who are overdosing

Narcan Dose Information

What is the typically administered dose of Narcan? Narcan nasal spray comes in 4 mg doses of naloxone hydrochloride in a 0.1 ml spray. The half-life of Narcan, or how long it takes for half of the drug to leave a person’s system, is approximately 60 minutes. With this half-life, the effects of Narcan will last for only a few hours after it is administered intranasally.

Narcan is not known to have any serious side effects for individuals who have not taken opioids or who were suspected (but not confirmed) of an overdose. In the event that it is accidentally sprayed up a person’s nasal cavity, it generally causes no harm. Narcan only works at blocking opioid signaling for anyone taking opioids or actively overdosing from opioids.

Administering Narcan

Individuals interested in how to administer Narcan will find that it is relatively easy, as it requires no prior medical training. Narcan administration involves a few key steps to ensure that the person who has overdosed will benefit from its use. Individuals should also be aware of what Narcan does once it begins to work. General steps that should be followed when administering Narcan include:

  1. Confirming an opioid overdose if possible
  2. Preparing the Narcan dose
  3. Administering Narcan nasal spray according to labeling instructions — a single spray of Narcan should be delivered patients intranasally into one nostril (not both)
  4. Call 911 for emergency assistance after or while administering the first dose of Narcan. If more than one person is around, have someone else call 911
  5. Monitor the person’s response
  6. Repeat Narcan administration with a new nasal spray dose if the person does not respond, or if they initially respond but then relapse into a respiratory depression (slow or stopped breathing). Doses can be given every two to three minutes until emergency medical services arrive on the scene
  7. Perform CPR and other resuscitative measures if multiple Narcan doses fail to work while waiting for emergency crews to arrive

What Happens After Administering Narcan for Overdose?

There are several side effects of Narcan use after an overdose. After the intranasal administration of Narcan, side effects are typically not severe and resolve relatively quickly. How well someone reacts to Narcan will depend on the person and the severity of their overdose.

It is important to note that Narcan will not reverse the effects of other drug classes like alcoholmarijuanacocaine or amphetamines. Narcan only reverses the effects of opioids, due to its mechanism of action.

Who Should Use Narcan?

Narcan nasal spray was designed for people who are experiencing an opioid overdose. However, it can be administered easily by virtually anyone. Narcan can be bought with or without a prescription from any major drugstore. Individuals who struggle with opioid use can buy it and have it on hand for others to administer in case of emergencies.

Administration of Narcan requires no medical training or background. Anyone who knows a person struggling with opioid addiction or lives in a community with high opioid use would likely benefit from carrying Narcan with them.

What Drugs Does Narcan Reverse?

What are the drugs that Narcan is most commonly used for? Narcan is most widely used to reverse the effects of all opioids currently available via prescription or on the street.

Narcan for heroin overdose is a common use of the medication. Additionally, Narcan can reverse a synthetic opioid known as Fentanyl. Many synthetic opioids are much more potent than naturally occurring opioids like heroin, but Narcan should still be effective at reversing their effects in cases of overdose.

Related Topic: heroin overdose

Narcan for opioid overdose works for many types of opioid drugs, including:

Narcan Side Effects

Though Narcan side effects are rare, they can still occur. However, the effects of overdosing far outweigh any secondary effects of using Narcan. The person who administered Narcan should monitor the person who overdosed and make sure no serious Narcan effects occur. Allergic reactions to naloxone HCl are especially rare.

Other rare side effects of Narcan use include acute opioid withdrawal, which causes:

  • Body aches
  • Elevated heart rate
  • Increased irritability or agitation
  • Convulsions
  • Upset stomach

Narcan Contraindications

According to the FDA, there is only one major contraindication for Narcan use. The one Narcan contraindication is that hypersensitive individuals to naloxone HCL or other ingredients in Narcan nasal spray should not be administered this drug.

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Narcan Statistics

According to the National Institute on Drug Abuse, the main ingredient in Narcan, naloxone HCl, has saved many lives in the past few years. Narcan facts include that in 2015, if Narcan had been available, it could have been used to reverse over 33,000 opioid overdose deaths. Other Narcan statistics include:

  • In Massachusetts, naloxone administration reduced opioid overdose deaths by about 11% in 19 different communities
  • 26,500 opioid overdoses in the United States were reversed using naloxone from 1996 to 2014
  • As of 2015, there has been no reported evidence of serious or life-threatening adverse reactions from using naloxone for treating an overdose

View Sources

Adapt Pharma. “GETTING NARCAN® IS SIMPLE.” 2018. Accessed July 16, 2019.

Adapt Pharma. “WHAT IS NARCAN® NASAL SPRAY?” 2018. Accessed July 16, 2019.

Harm Reduction Coalition. “Overdose Questions: Naloxone.” (n.d.). Accessed July 16, 2019.

Lynn, Rachael; Galinkin, J.L. “Naloxone dosage for opioid reversal: current evidence and clinical implications.” Therapeutic Advances in Drug Safety, January 2018. Accessed July 16, 2019.

National Institute on Drug Abuse. “Opioid Overdose Reversal with Naloxone (Narcan, Evzio).” April 2018. Accessed July 16, 2019.

National Institute on Drug Abuse. “Naloxone for Opioid Overdose: Life-Saving Science.” March 2017. Accessed July 16, 2019.

United States Food and Drug Administration. “FDA moves quickly to approve easy-to-use nasal spray to treat opioid overdose.” November 18, 2015. Accessed July 16, 2019.

United States Food and Drug Administration. “Highlights of Prescribing Information (Narcan®).” November 2015. Accessed July 16, 2019.

SAMHSA. “OTP Directory.” 2019.  Accessed July 15, 2019.

SAMHSA.  “Trends in the Use of Methadone, Buprenorphine, and Extended-Release Naltrexone at Substance Abuse Treatment Facilities: 2003-2015 (Update).” 2015. Accessed July 15, 2019.