What do smack, dragon, horse, salt, brown sugar, china white, and black pearl have in common? That’s right… they are all nicknames for heroin. We all know that Naloxone (Narcan) is a useful antidote in overdose, however appropriate dosing and timing can be more of an art than a science.
The most important concept to remember is that you are looking to treat respiratory depression, not restore a normal level of consciousness. You can always give more if needed, but putting a patient into acute withdrawal will do you (and your patient) more harm than good.
Many physicians start with 0.4mg IV, but this can be too large of a dose for many patients. If the patient has spontaneous respirations, try taking that 0.4mg dose and diluting it with 9cc of normal saline. You now have a 10mL syringe with 0.4mg of Narcan, which is 0.04mg/mL. You can give 1mL aliquots until the respiratory rate improves to greater than 12.
For large overdoses or longer acting opioids, repeated dosing may be necessary. For those of us who don’t have time to run to the bedside every 30 mins, a narcan drip may be useful. If you take 2/3 of the bolus dose needed to reverse respiratory depression and infuse this every hour you will maintain plasma naloxone levels (Goldfrank et al. 1986).
TL;DR
Titrate Narcan to RR >12, not normal mental status
Narcan Bolus: 0.4mg naloxone + 9cc normal saline = 10cc of 0.04mg/cc naloxone (give 1cc aliquots)
Narcan Drip: (mg of naloxone needed to reverse respiratory depression) x (2/3) = (mg per hour)
Sources:
Goldfrank L, et al. A dosing nomogram for continuous infusion intravenous naloxone. Ann Emerg Med. 1986 May;15(5):566-70.
Stolbach, A and Hoffman, RS. Acute opioid intoxication in adults. In UpToDate, Traub, SJ (Ed) UpToDate, Waltham, MA, 2018
Blue Magic. Digital Image. We Are The Mighty. 2019, https://www.wearethemighty.com/news/how-drug-dealers-used-the-us-military-to-smuggle-heroin
