IV · IM · SC · Intranasal · IO · Endotracheal (last resort)
Onset
IV 1–2 minutes; IM/intranasal 2–5 minutes
Duration
30–90 minutes — shorter than many opioids
Mechanism of action
Competitive opioid receptor antagonist (mu > kappa, delta). Displaces opioids and reverses respiratory depression, sedation and miosis.
Dosing
Adult
0.04–0.4 mg IV, titrated every 2–3 minutes to adequate breathing (start low in opioid-dependent patients); up to 2 mg IV/IM per dose in overdose. Intranasal 4 mg (one spray), repeat in 2–3 minutes in the other nostril
Pediatric
0.1 mg/kg IV/IO/IM (max 2 mg) for full reversal; lower titrated doses for therapeutic opioid excess
Not recommended during the initial steps of neonatal resuscitation; support ventilation first.
Indications
Opioid-induced respiratory depression or overdose
Suspected opioid overdose by lay rescuers (intranasal or IM) as part of BLS
Contraindications
Hypersensitivity to naloxone
Side effects
Acute opioid withdrawal in dependent patients (agitation, vomiting, tachycardia, hypertension)
Non-cardiogenic pulmonary edema (rare)
Arrhythmias (rare)
Return of pain in post-operative patients
Monitoring parameters
Respiratory rate, SpO2 and ETCO2
Level of consciousness
Observe for re-sedation for at least 2 hours (longer for long-acting opioids)
Drug interactions
Reverses opioid analgesia
No effect on benzodiazepine, alcohol or other non-opioid sedation