Naloxone

Provider Level

EMT/AEMT/RN/Paramedic

Class

Opioid antagonist

Mechanism of Action

Competitively binds to opioid receptors in the central nervous system, displacing opioid agonists and reversing their effects, particularly respiratory depression and sedation.

Indications

Reversal of respiratory depression induced by natural or synthetic opioids; coma of unknown etiology with suspected opioid overdose.

Contraindications

Known hypersensitivity to naloxone.

Routes

IM, SQ, IV, IO, ET

Onset / Duration

Onset is 1 to 2 minutes for IV/IO and 2 to 5 minutes for IM/SQ. Duration is 30 to 60 minutes depending on the route and dose.

Adverse Effects

Acute withdrawal syndrome including nausea, vomiting, sweating, tachycardia, hypertension, tremors, seizures, and combativeness. Rare but potential risk of flash pulmonary edema.

Precautions & Interactions

The duration of action of many opioids exceeds that of naloxone, meaning the patient may relapse into respiratory depression and require repeated administration. Use with caution in opioid-dependent patients including neonates of opioid-addicted mothers as it can precipitate severe withdrawal.

Special Considerations

Titrate to adequate respiratory rate and tidal volume rather than full consciousness to prevent sudden and severe withdrawal symptoms. Be prepared for vomiting and combativeness. Ensure adequate ventilation and oxygenation alongside administration.