How long does Narcan (naloxone) block opiates?

Official answer

by Drugs.com

Key Points

What is naloxone?

Narcan (generic name: naloxone) is a treatment often used to reverse the effects of an opioid overdose. It is available as an injection and as nasal spray. It was approved by the FDA as an over-the-counter (OTC) product in March 2023.

Prescription opioids are narcotic drugs often used for moderate-to-severe pain and include medicines such as hydrocodone, oxycodone, fentanyl and morphine. Heroin, an illegal drug of abuse, is also an opiate.

Narcan (naloxone) is classified as an opioid antagonist which means that it blocks opiate receptors in the brain and other areas of the body. Naloxone and opioids compete for the same receptor sites. By occupying the receptor and blocking the action of the opioid, naloxone can help to reverse the dangerous effects of an opioid overdose.

Evidence suggests that naloxone reverses opioid effects by competing for the opiate receptor sites in the central nervous system (CNS), with the greatest affinity for the mu receptor.

Does Narcan work for buprenorphine overdose?

The effects of Narcan on slowed or stopped breathing by partial agonists or mixed agonist/ / antagonists, such as buprenorphine and pentazocine, may be incomplete and may require repeat doses or higher doses of Narcan (naloxone).

For example, buprenorphine has a long duration of action in the body and is more slowly displaced from the opioid receptor. Larger or repeat doses of naloxone may be needed to block buprenorphine effects and to reverse prolonged respiratory depression.

In April 2021, Kloxxado (naloxone nasal spray) from Hikma Pharmaceuticals was approved to treat known or suspected opioid overdoses in adults and children.

Where can I get Narcan?

Narcan (naloxone) is now available at most major U.S. pharmacies without a prescription. If you or anyone in your family takes opioid medications, you should strongly consider having naloxone on hand for an emergency situation. Overdoses can occur by accident or intentionally.

Naloxone comes in different forms and can be given either as an injection or a nasal spray. Some forms of naloxone, such as Narcan Nasal Spray, are more user-friendly and can be given by the lay public, family members, caregivers or friends until emergency medical help arrives.

In March 2023, the FDA approved an over-the-counter (OTC) version of Narcan Nasal Spray, but it is not expected to be on retail shelves until late summer 2023. In the meantime, the prescription product will remain readily available from the pharmacist and through community distribution programs in accordance with state laws.

Patients and family members or caregivers, once they get their naloxone product, should read the FDA-approved patient labeling or Drug Facts Label before an emergency occurs. In those that elect to carry the devices or store these medications in their home, learning how to use them ahead of time can save important time.

How much does Narcan cost?

Narcan Nasal Spray

Any form of naloxone is NOT a substitute for emergency medical care, and 911 or other emergency medical care should be contacted immediately after administering naloxone in any form. Keep the person who has overdosed under surveillance until emergency personnel arrive.

This is not all the information you need to know about naloxone for safe and effective use in an emergency overdose. Review the full Narcan (naloxone) information here before an emergency overdose situation occurs, and discuss this information with your doctor or other health care provider.