Naloxone (a.k.a. Narcan, a.k.a. Vitamin N)

26 Apr


-Pure competitive antagonist at all opioid receptors

-Fully reverses all effects of opioids (respiratory depression, CNS depression, AND analgesia)

Onset is 1-2 minutes with duration of action 20-90 minutes


Dosing of Naloxone

For opioid dependent patients with mental status depression but only MINIMAL respiratory depression, initial starting dose of 0.05mg IV is recommended

            -High doses can make patients combative by causing withdrawal symptoms!

For opioid naïve patients also with CNS depression but minimal respiratory depression, starting dose of 0.4mg IV is recommended

-Repeat doses between 0.05 to 0.4mg IV can be given until you reach the desired mental status

– For patients with apnea and/or cyanosis, 2mg IV naloxone should be given REGARDLESS of their drug use history. 

-Repeated doses of 2mg IV can be given every 2-3 minutes until a maximum of 10mg IV is given


Naloxone Infusions

-Naloxone is a short acting medication so often it is of shorter duration than the opiate taken by the patient requiring re-doses

-Infusions should only be given if patients responded to repeated boluses

-Calculating dose

            –Determine “wake up dose” and given 2/3 of that dose per hour by IV infusion



Heroin exposure:  Discharge safely if meet following criteria 1-2 hours after naloxone

  • Independent mobility,
  • oxygen saturation >92% on room air,
  • RR >10,
  • HR >50,
  • GCS 15

Non-heroin overdose:  Generally require at least 4-6 hours of observation except for certain long acting opiates such as methadone


Submitted by J. Grover.


Sources: Tintinalli’s Emergency Medicine:  7th Edition.; picture

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