What is the recommended dose of Naloxone (Narcan) for parental administration?

Naloxone Dosing for Parenteral Administration in Opioid Overdose

For parenteral administration of naloxone in opioid overdose, the recommended initial dose is 0.4-2 mg intravenously, which may be repeated every 2-3 minutes until respiratory function improves. 1

Adult Dosing Guidelines

Intravenous Administration (Preferred in Emergency)

• Initial dose: 0.4-2 mg IV 2
• May repeat every 2-3 minutes if needed 1
• If no response after 10 mg total, question opioid-induced toxicity diagnosis 2
• For opioid-dependent patients, consider lower initial doses (0.04-0.4 mg) to minimize withdrawal 1

Intramuscular/Subcutaneous Administration

• Use if IV access is unavailable 2
• Same dosing as IV: 0.4-2 mg 2
• May repeat as needed based on response 2

Continuous Infusion (For Prolonged Cases)

• May be diluted in 0.9% sodium chloride or 5% dextrose 2
• Standard concentration: 2 mg in 500 mL (0.004 mg/mL) 2
• Titrate rate according to patient response 2
• Discard solution after 24 hours 2

Pediatric Dosing Guidelines

Known or Suspected Opioid Overdose

• Initial dose: 0.01 mg/kg body weight IV/IM/SC 2
• If inadequate response, may increase to 0.1 mg/kg body weight 2
• For children, the American Academy of Pediatrics supports this dosing approach 1

Postoperative Opioid Depression

• Initial dose: 0.005-0.01 mg/kg IV 2
• Administer in increments at 2-3 minute intervals 2
• Titrate to desired degree of reversal 2

Route of Administration Considerations

The route of administration affects onset of action:

• IV: Fastest onset (1-2 minutes) 1
• IM/SC: Slower onset but useful when IV access unavailable 2
• Intranasal: Alternative when parenteral access is difficult (2 mg standard dose) 1

Clinical Approach Algorithm

1. Assess airway and breathing

   • Begin rescue breathing if necessary before naloxone administration 1

2. Choose appropriate route based on access

   • IV preferred for fastest onset
   • IM/SC if IV unavailable

3. Administer initial dose

   • Adults: 0.4-2 mg IV/IM/SC
   • Children: 0.01 mg/kg IV/IM/SC

4. Reassess after 2-3 minutes

   • If inadequate response, repeat dose
   • For adults, may increase to higher dose within range
   • For children, may increase to 0.1 mg/kg if needed

5. Monitor for at least 2 hours after last dose

   • Naloxone's duration of action (30-45 minutes) is shorter than many opioids 1
   • Be prepared for recurrent respiratory depression

Important Clinical Considerations

• Titrate carefully: Aim to restore adequate respiration without precipitating severe withdrawal 1
• Avoid excessive dosing: Large doses in opioid-dependent patients can cause severe withdrawal (hypertension, tachycardia, vomiting, agitation) 1
• Prepare for multiple doses: The duration of action of naloxone (30-45 minutes) is shorter than many opioids, especially long-acting formulations 1
• Do not mix with: Solutions containing bisulfite, metabisulfite, long-chain anions, or alkaline pH solutions 2

Special Situations

• Partial reversal post-surgery: Use smaller doses (0.1-0.2 mg IV increments) to avoid complete reversal of analgesia 2
• Septic shock: Optimal dosage not established 2
• Suspected fentanyl overdose: May require higher or more frequent doses due to potency 3

The evidence strongly supports using appropriate parenteral naloxone dosing based on age, clinical situation, and route of administration, with careful monitoring for at least 2 hours after the last dose to ensure sustained reversal of opioid effects.