What are the indications for Naloxone (Narcan)?

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From the Guidelines

Indications for Naloxone (Narcan)

Naloxone is indicated for the reversal of opioid overdose, including respiratory depression, in patients who have received an overdose of opioids such as heroin, morphine, or fentanyl 1.

  • The recommended dose is 0.4 to 2 milligrams administered intravenously, intramuscularly, or subcutaneously, and may be repeated every 2 to 3 minutes as needed, up to a maximum dose of 10 milligrams 1.
  • For patients who are unconscious or not breathing, naloxone should be administered immediately, along with cardiopulmonary resuscitation if necessary 1.
  • Naloxone can also be used to reverse severe life-threatening instability (such as severe CNS or respiratory depression, hypotension, or cardiac arrhythmia) that is suspected to be due to opioid toxicity 1.
  • Patients who respond to naloxone administration may develop recurrent CNS and/or respiratory depression, and longer periods of observation may be required to safely discharge a patient with life-threatening overdose of a long-acting or sustained-release opioid 1.
  • Post-cardiac arrest care may also involve naloxone administration to achieve the specific therapeutic goals of reversing the effects of long-acting opioids 1.

From the FDA Drug Label

Naloxone Hydrochloride Injection, USP is indicated for the complete or partial reversal of opioid depression, including respiratory depression, induced by natural and synthetic opioids, including propoxyphene, methadone, and certain mixed agonist-antagonist analgesics: nalbuphine, pentazocine, butorphanol, and cyclazocine. Naloxone Hydrochloride Injection, USP is also indicated for diagnosis of suspected or known acute opioid overdosage. The indications for Naloxone (Narcan) are:

  • Reversal of opioid depression, including respiratory depression
  • Diagnosis of suspected or known acute opioid overdosage
  • Adjunctive use in septic shock to increase blood pressure 2

From the Research

Indications for Naloxone (Narcan)

  • Naloxone is indicated for the reversal of opioid-induced respiratory depression 3, 4, 5, 6, 7
  • It is used to reverse the respiratory and central nervous system-depressant effects of opioids 3
  • Naloxone can be administered via various routes, including intranasal, intravenous, intramuscular, and subcutaneous routes 3, 4, 7
  • The intranasal route is effective in treating opioid overdose when intravenous administration is impossible or undesirable 3

Reversal of Opioid-Induced Respiratory Depression

  • Naloxone has been shown to reverse opioid-induced respiratory depression in 74% and 72% of patients in two randomized controlled trials 3
  • In a study, naloxone reversed respiratory depression in 83.3% of episodes 5
  • Naloxone can also reverse opioid-induced ventilatory depression, with a median dose of 0.08 mg reversing depression in 15 ED patients 7

Comparison of Naloxone Dosing Regimens

  • A retrospective cohort study compared the rates of opioid withdrawal symptoms and reversal of opioid toxicity in patients treated with two naloxone dosing regimens 6
  • The study found that high-dose naloxone patients were more likely to have opioid withdrawal symptoms and meet reversal criteria than low-dose naloxone patients 6
  • Another study found that low-dose naloxone (0.04 mg) can be effective in reversing opioid-induced ventilatory depression with appropriate dose titration 7

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Intranasal naloxone administration for treatment of opioid overdose.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 2014

Research

Patterns of naloxone use in hospitalized patients.

Postgraduate medicine, 2017

Research

Reversal of Opioid-Induced Ventilatory Depression Using Low-Dose Naloxone (0.04 mg): a Case Series.

Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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