From the Guidelines
The recommended dose for intramuscular (IM) administration of Narcan (naloxone) is 0.2–2 mg, as indicated in the 2023 American Heart Association guidelines 1. When administering Narcan IM, it is essential to follow the guidelines to ensure effective reversal of opioid overdose.
- The dose can be repeated every 2-3 minutes as needed if there is no response, with a maximum total dose generally not exceeding the cumulative dose required to achieve reversal of respiratory depression.
- It is crucial to inject the medication into a large muscle, such as the deltoid (upper arm), vastus lateralis (thigh), or gluteal muscle (buttock), to facilitate rapid absorption.
- The onset of action for IM administration is typically 2-5 minutes, which is slower than intravenous administration but still effective in emergency situations.
- Naloxone has a shorter duration of action (30-90 minutes) than many opioids, so patients may require repeated doses or continuous monitoring as the naloxone wears off.
- After administering Narcan, it is vital to seek immediate medical attention, as the patient may experience withdrawal symptoms or require additional medical care. The American Heart Association guidelines 1 emphasize the importance of titrating the dose to reversal of respiratory depression and restoration of protective airway reflexes, highlighting the need for careful monitoring and adjustment of the dose as needed.
From the Research
Recommended Dose for Intramuscular Administration of Narcan
- The recommended dose for intramuscular (IM) administration of Narcan (naloxone) is 0.4 mg or 0.8 mg 2.
- A study found that emergency medical staff appear to titrate naloxone based on clinical presentation, with unconscious patients or those in respiratory arrest more likely to be treated with 0.8 mg naloxone and to receive multiple doses 2.
- Another study compared the pharmacokinetic properties of intranasal naloxone to an approved 0.4 mg intramuscular dose, but did not provide information on the optimal dose for IM administration 3.
Administration of Narcan via IM Route
- Intramuscular naloxone doses of 0.4 and 0.8 mg were found to be effective and safe in the treatment of opioid overdose in the prehospital setting 2.
- A meta-analysis found that injectable (intramuscular/intravenous) naloxone and intranasal naloxone had similar success rates in the pre-hospital management of opioid overdose, but the onset of action of intranasal naloxone was slightly longer than injectable naloxone 4.
- A study found that intramuscular naloxone administration was more effective than intranasal naloxone administration in reversing opioid overdose, with clients randomized to intramuscular naloxone administration less likely to require a rescue dose of naloxone 5.