Recommended Naloxone (Narcan) Dosing for Opioid Overdose
For suspected opioid overdose, the recommended dose of OTC Narcan (naloxone) is 2 mg intranasally, which can be repeated in 3-5 minutes if no response occurs. 1
Dosing by Administration Route
- Intranasal (OTC Narcan): 2 mg per dose, repeated in 3-5 minutes if necessary 1, 2
- Intramuscular: 0.4-2 mg per dose, repeated every 2-3 minutes as needed 3, 4
- Intravenous: 0.4-2 mg initially, repeated every 2-3 minutes as needed 3
Clinical Considerations
Patient Assessment
- Prioritize airway management and breathing support before naloxone administration 5
- Administer naloxone to patients with suspected opioid overdose who have a pulse but no normal breathing or only gasping 5
- Continue standard BLS/ACLS care regardless of naloxone administration 5
Dosing Considerations
- Higher doses may be required for synthetic opioid overdoses (e.g., fentanyl) 4
- Use the lowest effective dose to minimize withdrawal symptoms while restoring respiration 1
- Most reversals (97.6%) involve administration of ≤2 units of intranasal naloxone 2
Response Time
- Most patients (73.5%) respond within 5 minutes of intranasal naloxone administration 2
- Average response time to intranasal naloxone is approximately 3.4 minutes 6
Important Caveats
- Naloxone's duration of action (1-2 hours) may be shorter than the respiratory depressant effects of many opioids, particularly long-acting formulations 5
- Patients should be observed in a healthcare setting until risk of recurrent opioid toxicity is low and vital signs have normalized 5
- Naloxone will not reverse respiratory depression due to non-opioid substances such as benzodiazepines 1
- Naloxone may precipitate acute withdrawal syndrome in opioid-dependent patients 1
Special Populations
- Pediatric patients: 0.1 mg/kg body weight IV initially; if inadequate response, may administer 0.1 mg/kg body weight 3
- Patients with renal impairment: Standard dosing applies, but more frequent monitoring is recommended 5