Narcan

Narcan is a brand name for naloxone, a medication that blocks opioid receptors and is used to reverse potentially life-threatening opioid overdoses. Naloxone works by binding to mu, kappa, and delta receptors more strongly than most opioids, displacing opioid molecules and reversing respiratory depression and sedation caused by heroin, fentanyl, prescription pain medicines, and other opioids.

Formulations and administration: Naloxone is available in injectable forms for intramuscular, intravenous, or subcutaneous use, and in an intranasal spray form (Narcan Nasal Spray) for lay administration. Auto-injector versions exist for non-medical responders. In an overdose situation, responders administer naloxone as soon as overdose is suspected and seek emergency medical care. If symptoms persist, additional doses may be required as guided by product labeling and medical direction. Intranasal administration typically involves delivering one or more sprays into the nostrils.

Onset and duration: Nasal naloxone generally begins to work within a few minutes; injectable routes can act more quickly. Naloxone’s effects wear off relatively quickly (about 30 to 90 minutes), whereas some opioids last longer, creating a risk of recurrent overdose symptoms after naloxone wears off. Patients require monitoring and possible follow-up treatment.

Safety and adverse effects: Naloxone is generally safe, but sudden withdrawal symptoms can occur in people dependent on opioids, causing agitation, nausea, vomiting, tachycardia, or hypertension. It should not be used for non-opioid overdoses. Contraindications include known hypersensitivity to naloxone.

Availability and history: Naloxone was developed in the mid-20th century and approved for medical use in multiple countries, with Narcan nasal spray introduced to facilitate non-prescription use. Generic naloxone products are widely available, and the medication is a common component of overdose prevention programs and emergency response kits.