Naloxone
Reverses opioid toxicity. Titrate IV to breathing, not to full wakefulness; it wears off before many opioids do.
On this page
Uses
- Opioid overdose.
- Respiratory depression from therapeutic opioids.
Adult dose
| Situation | Dose |
|---|---|
| Overdose with low breathing | 400 micrograms IV, repeat every 2–3 minutes to effect (larger doses for some synthetic opioids) |
| Therapeutic opioid toxicity, opioid-dependent patients | 100–200 micrograms IV, repeat every 2–3 minutes |
| IM (no IV access) | 400 micrograms |
| Infusion | About two-thirds of the effective initial dose per hour, titrated |
Children's dose
10 micrograms/kg IV, then 100 micrograms/kg if no response (overdose); 1–4 micrograms/kg for therapeutic opioid toxicity.
Side effects and cautions
- Acute withdrawal, severe pain, agitation in opioid-dependent patients.
- Re-sedation as naloxone wears off (30–90 minutes).
Frequently asked questions
How long does naloxone last?
Usually 30–90 minutes, shorter than many opioids, so patients need monitoring and sometimes an infusion.
Used in these guides
Sources
Doses on this page are typical doses from the sources above. Always confirm with a current drug reference, the product leaflet and your hospital protocol, especially in children, pregnancy and kidney or liver disease.
For FCPS Part 1
Revising for FCPS Part 1? Naloxone is covered in our textbook chapter Analgesics and NSAIDs, with practice MCQs.