National Stroke Foundation

Narcan (naloxone hydrochloride)

The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.


Approval Status:

Approved November 2015

Specific Treatments:

emergency treatment of known or suspected opioid overdose

Therapeutic Areas

General Information

Narcan (naloxone hydrochloride) is an opioid antagonist.

Narcan is specifically indicated for the emergency treatment of known or suspected opioid overdose, as manifested by respiratory and/or central nervous system depression. 

Narcan is supplied as a spray for nasal administration. The recommended initial dose of Narcan Nasal Spray in adults and pediatric patients is one spray delivered by intranasal administration, which delivers 4 mg of naloxone hydrochloride. Administer Narcan Nasal Spray as quickly as possible because prolonged respiratory depression may result in damage to the central nervous system or death. Do not attempt to reuse Narcan Nasal Spray. Each nasal spray contains a single dose of naloxone and cannot be reused. Re-administer Narcan Nasal Spray, using a new nasal spray, every 2 to 3 minutes if the patient does not respond or responds and then relapses into respiratory depression. Administer Narcan Nasal Spray in alternate nostrils with each dose. Please see drug label for specific dosing instructions.

Clinical Results

FDA Approval

In clinical trials conducted to support the approval of Narcan nasal spray, administering the drug in one nostril delivered approximately the same levels or higher of naloxone as a single dose of an FDA-approved naloxone intramuscular injection, and achieved these levels in approximately the same time frame.

Side Effects

Adverse effects associated with the use of Narcan may include, but are not limited to, the following:

  • increased blood pressure
  • musculoskeletal pain
  • headache
  • nasal dryness
  • nasal edema
  • nasal congestion
  • nasal inflammation

Mechanism of Action

Narcan (naloxone hydrochloride) is an opioid antagonist that antagonizes opioid effects by competing for the same receptor sites. Naloxone hydrochloride reverses the effects of opioids, including respiratory depression, sedation, and hypotension. It can also reverse the psychotomimetic and dysphoric effects of agonist-antagonists such as pentazocine.

Additional Information

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