What is the dose of Naloxone (Narcan)?

From the Guidelines

The standard dose of Narcan (naloxone) for opioid overdose is 0.4 to 2 mg administered intravenously, intramuscularly, or subcutaneously, which can be repeated every 2-3 minutes as needed, as recommended by the most recent guidelines 1. For intranasal administration, the recommended dose is 4 mg (one spray in one nostril), which can be repeated after 2-3 minutes if there is no response. In community settings, the prefilled nasal spray device (Narcan Nasal Spray) containing 4 mg is most commonly used due to its ease of administration. After administering Narcan, it's crucial to monitor the person closely as its effects typically last 30-90 minutes, which is shorter than most opioids, potentially leading to a return of overdose symptoms when Narcan wears off. Medical attention should be sought immediately after administration, even if the person appears to recover, as they may need additional doses or monitoring. Narcan works by competitively binding to opioid receptors, displacing the opioids and rapidly reversing respiratory depression, which is the primary cause of death in opioid overdose, as supported by the 2024 American Heart Association and American Red Cross guidelines for first aid 1. The ideal dose of naloxone is not known, but the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care recommend an empiric starting dose of 0.04 to 0.4 mg IV or intramuscular (IM) to avoid provoking severe opioid withdrawal in patients with opioid dependency 1. However, the most recent guidelines from 2024 suggest a dose of 2 mg intranasal or 0.4 mg intramuscular, which may be repeated after 4 minutes 1, prioritizing the safety and efficacy of naloxone administration in real-life clinical practice. Key considerations in naloxone administration include the potential for acute withdrawal syndrome in patients with opioid dependency and the importance of monitoring for signs of overdose recurrence after Narcan administration, as highlighted in the 2015 guidelines 1. Overall, the use of naloxone in opioid overdose reversal is supported by strong evidence, with the most recent guidelines emphasizing the importance of prompt administration and monitoring in preventing morbidity and mortality 1.

Key Points

• The standard dose of Narcan (naloxone) for opioid overdose is 0.4 to 2 mg administered intravenously, intramuscularly, or subcutaneously.
• For intranasal administration, the recommended dose is 4 mg (one spray in one nostril).
• Medical attention should be sought immediately after administration, even if the person appears to recover.
• Narcan works by competitively binding to opioid receptors, displacing the opioids and rapidly reversing respiratory depression.
• The most recent guidelines from 2024 prioritize the safety and efficacy of naloxone administration in real-life clinical practice 1.

Administration Considerations

• Monitor the person closely after administering Narcan, as its effects typically last 30-90 minutes.
• Be aware of the potential for acute withdrawal syndrome in patients with opioid dependency.
• Repeat doses may be necessary if there is no response after 2-3 minutes.
• The prefilled nasal spray device (Narcan Nasal Spray) containing 4 mg is most commonly used in community settings due to its ease of administration.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Naloxone Hydrochloride Injection, USP may be administered intravenously, intramuscularly, or subcutaneously. Usage in Adults Opioid Overdose - Known or Suspected: An initial dose of 0. 4 mg to 2 mg of naloxone hydrochloride may be administered intravenously. Usage in Children Opioid Overdose - Known or Suspected: The usual initial dose in children is 0. 01 mg/kg body weight given IV. Usage in Neonates Opioid-Induced Depression: The usual initial dose is 0. 01 mg/kg body weight administered IV, IM, or SC.

The recommended dose of Narcan (naloxone) is:

• Adults: 0.4 mg to 2 mg intravenously for opioid overdose
• Children: 0.01 mg/kg body weight given intravenously for opioid overdose
• Neonates: 0.01 mg/kg body weight administered intravenously, intramuscularly, or subcutaneously for opioid-induced depression 2

From the Research

Narcan Dose Information

• The recommended dose of Narcan (naloxone) can vary depending on the individual and the circumstances of the overdose, with studies suggesting doses ranging from 0.05 mg to 4 mg or more 3, 4, 5.
• A study comparing the pharmacokinetic properties of intranasal naloxone (2 to 8 mg) delivered in low volumes (0.1 to 0.2 mL) using an Aptar Unit-Dose device to an approved (0.4 mg) intramuscular dose found that all doses of intranasal naloxone resulted in plasma concentrations and areas under the curve greater than those observed following the intramuscular dose 3.
• Another study found that a 4-mg dose delivered in a single device (0.1 mL) was selected as the final product, which can be used by first responders and the lay public to provide an important and potentially life-saving intervention for victims of an opioid overdose 3.
• The risks related to naloxone use in opioid-dependent patients include the induction of an acute withdrawal syndrome, the effect of naloxone may wear off prematurely, and high-dose naloxone and/or rapidly infused naloxone may cause catecholamine release and consequently pulmonary edema and cardiac arrhythmias 4.
• A study examining outcomes following naloxone administration by bystanders and first responders found that factors associated with increased rate of hospital admission included higher total naloxone dosage and presence of alternate/additional non-opioid central nervous system (CNS) depressants 6.

Dosing Considerations

• The optimal naloxone dose is unclear, and few studies address this question, with variations in recommended doses spanning an order of magnitude 5.
• More than half of medical toxicology and general medical sources recommend a low-dose strategy with a starting dose lower than 0.05 mg IV 5.
• A study found that administration of additional naloxone by paramedics was not associated with a higher rate of neurologic improvement prior to hospital arrival, suggesting a ceiling effect on naloxone efficacy in opioid overdose 6.