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Pronunciation: naar-kan
Generic name: naloxone
Dosage form: Nasal spray
Drug class: Antidotes

Medically reviewed by Melisa Puckey, BPharm. Last updated on Jul 11, 2024.

What is Narcan?

Narcan (naloxone) nasal spray is an over-the-counter medicine used to treat an opioid overdose emergency, Narcan works by rapidly reversing the opioid's effects. Naran should be given as soon as possible when an opioid overdose is suspected, and then the patient should also receive emergency medical care immediately, even if they wake up.

Narcan nasal spray became FDA-approved on March 29, 2023, as an over-the-counter (OTC) medicine without the need for a prescription, however, it is unknown when the OTC Narcan nasal spray product will be available. Until the OTC nasal spray becomes available, the nasal spray with the prescription label will still be available from a pharmacist without a prescription from your doctor under state Naloxone Access Laws or alternate arrangements.

Narcan nasal spray can be used for adults and children for known or suspected opioid overdose if there are signs of slowed breathing, severe sleepiness, or the person is not able to respond (loss of consciousness).

Narcan works to block the opioid effect as it is an opioid antagonist as it competes for the opiate receptors in the brain and other areas of the body to help reverse the dangerous effects of the opioid so that the patient's breathing improves and they become more awake, and their blood pressure normalizes.

Examples of opioids are codeine, oxycodone (Oxycontin), heroin morphine, hydrocodone (Vicodin, Lortab), fentanyl, methadone, oxymorphone, meperidine, tramadol, buprenorphine, and hydromorphone.

Narcan was originally available as an njection, which has since been discontinued. The Narcan nasal spray is available as an over-the-counter medicine, so a prescription is NOT needed. 

Important information

Narcan is used to reverse the effects of opioid medicines temporarily, it will have no effect in people who are not taking opioid medicines. Always carry a nasal spray with you in case of an opioid overdose emergency.

Use Narcan as soon as possible if you or your caregiver think there are signs or symptoms of an opioid emergency, even if you are not sure because an opioid emergency can cause severe injury or death. Signs and symptoms of an opioid emergency may include:

You should know where the nasal spray is stored and how to give the nasal spray before an opioid emergency happens. This is important if you have family members, caregivers, or other people who are at risk of opioid overdose and may need to have Narcan administered in an opioid emergency.

After giving the first dose of this medicine, you need to get emergency medical help right away, even if the person wakes up. Rescue breathing or CPR (cardiopulmonary resuscitation) may be given while waiting for emergency medical help

The signs and symptoms of an opioid emergency can return after this medicine is given. If this happens, give another dose after 2 to 3 minutes using a new nasal spray device and watch the person closely until emergency help is received.

Before taking this medicine

You should not be treated with Narcan if you are allergic to naloxone or any of the ingredients in this nasal spray. Click here for a full list of Narcan ingredients

If possible before you receive Narcan, tell your doctor if:

If you use opioid medicine during pregnancy, your baby could be born with life-threatening withdrawal symptoms, and may need medical treatment for several weeks.

Using Narcan while you are pregnant may also cause opioid withdrawal effects in your unborn baby. However, having an opioid overdose can be fatal to both mother and baby. It is much more important to treat an overdose in the mother. You must get emergency medical help after using this medicine. Be sure all emergency medical caregivers know that you are pregnant.

If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids may need medical treatment for several weeks.

In an emergency, you may not be able to tell caregivers if you are pregnant or breastfeeding. Make sure any doctor caring for your pregnancy or your baby knows you received Narcan.

How should I use Narcan?

Use this medicine exactly as prescribed by your healthcare provider.

For more detailed instructions (with pictures) about the right way to use Narcan, read the "Instructions for Use" at the bottom of the Professional Narcan document.

Dosing information

Usual Adult and Pediatric Dose for Opioid Overdose:

Administer 1 spray intranasally into 1 nostril

If desired response is not achieved after 2 or 3 minutes, give a second dose from a new nasal spray device, intranasally into alternate nostrils; additional doses may be administered every 2 to 3 minutes in alternating nostrils until emergency medical assistance arrives.


What should I avoid while taking Narcan?

Avoid leaving a person alone after giving him or her a dose of this medicine. An overdose of naloxone can impair a person's thinking or reactions.

Narcan side effects

Get emergency medical help if you have signs of an allergic reaction to Narcan: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Because Narcan reverses opioid effects, its use may cause sudden withdrawal symptoms such as:

Sudden withdrawal symptoms in a baby younger than 4 weeks old may be life-threatening if not treated the right way. Symptoms include crying, stiffness, overactive reflexes, and seizures. Call your doctor or get emergency medical help if you are not sure how to properly give this medicine to a baby.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Narcan?

Other drugs may interact with naloxone, including prescription and over-the-counter medicines, vitamins, recreational drugs and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.



Active ingredient: naloxone hydrochloride

Inactive ingredients: benzalkonium chloride (preservative), disodium ethylenediaminetetraacetate (stabilizer), sodium chloride, hydrochloric acid to adjust pH and sterile water

Narcan is not made with natural rubber latex.


Distributed by Emergent Devices Inc., Plymouth Meeting, PA 19462 USA.

For more information, go to or call 1-844-4Narcan (1-844-462-7226).

Popular FAQ

There are several ways to get free Narcan (naloxone) emergency kits, which include, local syringe exchange programs, your insurance company, and state and local health departments or other community health services. Continue reading

Naloxone blocks opioid receptors from 30 to 120 minutes, but this can be variable and depends upon the dose and how it is given. Some patients may need repeat doses of naloxone. Continue reading

Narcan (naloxone) is available in different dose forms and can be given either as an injection or a nasal spray to reverse an opioid overdose. Continue reading

Narcan (naloxone) works in an overdose by reversing serious or deadly central nervous system (CNS) depression due to opioids (narcotics), including depressed breathing, extreme drowsiness and loss of consciousness. This effect usually occurs in minutes. Naloxone is considered a pure opioid antagonist and it works by blocking opioid receptors in the body. Continue reading

Naloxone is not a controlled substance, according to the US Drug Enforcement Administration (DEA). It is an opioid antagonist used to treat known or suspected opioid overdose, and naloxone nasal spray (sold under the brand name, Narcan) was FDA-approved for sale over-the-counter on March 29th, 2023. It should be available for purchase in places like drug stores, convenience stores, grocery stores and gas stations, as well as online, without a prescription from late summer. Narcan Nasal Spray and naloxone is still available from the pharmacist in all 50 states without a prescription from your doctor.

Naloxone is a centrally acting opioid receptor antagonist. Naloxone binds with the highest affinity to the mu-opioid receptor subtype in the central nervous system (CNS). Naloxone works to reverse opioid overdose and a form of naloxone (Narcan nasal spray) was FDA-approved for over-the-counter (OTC) sale on 29th March 2023.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.