What is the proper administration and dosage of Narcan (naloxone) in cases of suspected opioid overdose?

Narcan (Naloxone) Administration for Suspected Opioid Overdose

For a patient with suspected opioid overdose who is unresponsive and not breathing normally, immediately activate emergency services, provide high-quality CPR with rescue breathing, and administer naloxone without delay. 1

Immediate Assessment and Action Sequence

Step 1: Rapid Assessment (< 10 seconds)

• Check responsiveness and assess breathing and pulse simultaneously 2
• Activate emergency response system immediately—do not delay while awaiting response to naloxone 1, 2

Step 2: Determine Clinical Scenario

Scenario A: Respiratory Arrest (Pulse Present, No Normal Breathing)

• This is the primary indication for naloxone 1
• Open airway and provide rescue breathing or bag-mask ventilation immediately 1, 2
• Administer naloxone while continuing ventilatory support 1
• Maintain rescue breathing until spontaneous breathing returns 1

Scenario B: Cardiac Arrest (No Pulse)

• Prioritize high-quality CPR over naloxone administration 1
• Begin chest compressions and ventilations immediately 1
• Naloxone may be considered after CPR is initiated, but only if it does not delay compressions 1
• Naloxone is ineffective without chest compressions to deliver the drug to tissues 1

Naloxone Dosing and Administration Routes

Initial Dosing (Adults)

Intravenous Route (Preferred for titration):

• Initial dose: 0.4 to 2 mg IV 3
• Repeat every 2-3 minutes if respiratory function does not improve 3
• Maximum total dose: 10 mg (if no response after 10 mg, question the diagnosis) 3

Intranasal Route (Equally recommended to IV):

• Administer per device instructions 1
• May require rescue doses more frequently than IV route 4
• Onset of action slightly longer than injectable routes 4
• 8 mg intranasal formulations now available for synthetic opioid overdoses 5

Intramuscular/Subcutaneous Route (If IV unavailable):

• Use same dosing as IV 3
• Slower onset of action and more difficult to titrate 6
• Higher likelihood of needing rescue doses 4

Pediatric Dosing

• Initial dose: 0.01 mg/kg IV, IM, or SC 3
• If inadequate response, subsequent dose of 0.1 mg/kg may be given 3

Neonatal Dosing

• Initial dose: 0.01 mg/kg IV, IM, or SC 3

Critical Monitoring and Post-Administration Management

Immediate Post-Naloxone Monitoring:

• Observe for return of spontaneous breathing 1
• Monitor respiratory rate (goal ≥10 breaths/min) 7
• Assess level of consciousness 7
• Watch for signs of acute withdrawal (vomiting, agitation) 8

Observation Period Requirements:

• Minimum 2 hours after last naloxone dose for all patients 7, 2
• Abbreviated observation (2-4 hours) for immediate-release opioids 7
• Extended observation (6-8+ hours) for long-acting or sustained-release opioids 7
• Continue until vital signs normalized and risk of recurrent toxicity is low 1, 7

Management of Recurrent Toxicity:

• Naloxone duration of action is 45-70 minutes, shorter than most opioids 7
• If respiratory depression recurs, administer repeated small doses or continuous infusion 1, 7
• Continuous infusion preparation: 2 mg naloxone in 500 mL saline (0.004 mg/mL concentration) 3
• Titrate infusion rate to patient response 3

Common Pitfalls and How to Avoid Them

Pitfall 1: Delaying Emergency Activation

• Never wait to see if naloxone works before calling for help 1
• Naloxone is ineffective for non-opioid causes of respiratory depression 1

Pitfall 2: Administering Naloxone to Breathing Patients

• A person breathing normally does not require naloxone 1
• Focus on airway management and ventilatory support first 1

Pitfall 3: Premature Discharge

• Do not discharge patients who appear recovered after initial naloxone response 7
• Recurrent toxicity can occur hours later, especially with fentanyl and analogs 7, 5

Pitfall 4: Excessive Dosing

• Larger than necessary doses may cause severe withdrawal, hypertension, pulmonary edema, or cardiac arrhythmias 3, 8
• Titrate to adequate ventilation, not full consciousness 3

Pitfall 5: Assuming Naloxone Alone is Sufficient

• Synthetic opioids like fentanyl are 50 times more potent than heroin and may require higher doses 5
• Xylazine (increasingly common adulterant) does not respond to naloxone—hospitalization essential 5

Special Considerations

Synthetic Opioid Era:

• Fentanyl and analogs now account for ~90% of fatal overdoses 5
• Higher-dose formulations (5 mg injection, 8 mg intranasal) may be needed 5
• Multiple doses are frequently required 5

Safety Profile:

• Naloxone has excellent safety profile and is unlikely to cause harm if given to non-opioid respiratory depression 1
• Major complications are rare and dose-related 1
• Risk of acute withdrawal is present but preferable to death from respiratory arrest 8, 5

Training and Distribution:

• First aid providers should receive hands-on training in naloxone administration 1
• Opioid overdose education and naloxone distribution to at-risk individuals is beneficial 1
• Naloxone nasal spray is available without prescription in the United States 1