Naloxone Hydrochloride (Narcan®)

Section 1.1

Midwives may independently prescribe, order and administer this drug.

Naloxone hydrocholoride (Narcan®) is a narcotic antagonist used to treat opioid toxicity and overdose.

Note: The American Academy of Pediatrics (AAP) no longer recommends the use of naloxone hydrochloride (naloxone) for neonatal resuscitation at birth. There is insufficient data on the efficacy and short-term and long-term safety of naloxone to reverse respiratory depression in the neonate caused by maternal opiate exposure in labour close to the time of birth. There is also concern that naloxone is misused during resuscitation and could lead to seizures when administered to infants of opioid-dependent women. The Canadian Neonatal Resuscitation Program (NRP) Executive Committee is in agreement with this recommendation. Refer to the most current NRP recommendations for first-line treatment of neonatal respiratory depression.

Indications and Clinical Use:

To reverse opioid toxicity.


Previous hypersensitivity reaction to naloxone.

Warnings and Precautions:

Naloxone is not effective in reversing respiratory depression due to any other cause than opioid toxicity. Naloxone is not recommended for use during newborn resuscitation.


Compatible – No evidence of impaired fertility or fetal harm.

Naloxone crosses the placenta quickly and appears in fetal blood within 2 minutes following adult dose


Category L3 – No Human Data – Probably Compatible

Naloxone is considered suitable for use in lactation. This medication has a very short half-life (one hour), is poorly absorbed orally and plasma levels in adults are thought to be undetectable two hours after oral doses. When administering this medication to a breastfeeding client for a narcotic overdose, breastfeeding may need to be withheld due to the amount of narcotic in milk and potential risk of adverse effects including respiratory depression and sedation.

Adverse Reactions:

Adverse reactions are typically related to reversing dependency and precipitating withdrawal and include abdominal cramps, diarrhea, nausea, vomiting, muscle weakness, dyspnea, respiratory depression, restlessness, irritability, cardiac arrest, fever, hypertension, hypotension and/or tachycardia.

Dosage and Administration:

May be administered IV or IM routes. IM route not recommended due to slow onset of action and therapeutic effect.

Adult initial dose of naloxone for reversal of respiratory depression caused by a therapeutic dose of opioids:

  • IV: 0.04-0.4 mg, may repeat until desired response is achieved
  • IM: 0.04-0.4 mg, may repeat until desired response is achieved

Adult initial dose of naloxone cause by opioid overdose:

  • IV: 0.4-2 mg, may repeat until desired response is achieved
  • IM: 0.4-2 mg, may repeat until desired response is achieved

Additional considerations:

  • Consult physician following administration;
  • May need to repeat doses every two to three minutes and an IV infusion may be required (midwives are unable to prescribe a naloxone IV infusion);
  • Additional dose(s) may be required after reversal has occurred based on the opioids half-life.

Onset of Action:

IV: 2 minutes

IM: 2-5 minutes


Adult – 0.5-1.5 hours


Urine as metabolites