Narcan
Formal Definition
Trade name for naloxone; a competitive opioid receptor antagonist used to rapidly reverse opioid-induced respiratory depression, sedation, and miosis; available IV, IM, intranasal (Narcan nasal spray), or subcutaneous; onset 2–5 minutes IV, duration shorter than most opioids (30–90 min), requiring redosing or infusion for long-acting opioids.
How It's Used on the Ward
"Give them Narcan" or "reverse them" or "Narcan the patient" — the rescue medication for opioid overdose, now available over-the-counter as an intranasal spray.
Example
""EMS brings in a 34-year-old unresponsive with pinpoint pupils and respiratory rate of 4 — three doses of IM Narcan in the field, partially responsive. Starting IV naloxone infusion at two-thirds of the reversal dose per hour given the likely fentanyl exposure.""
Clinical Context
Starting IV dose: 0.4–2 mg (titrate to respiratory rate/sedation, not complete reversal — avoids precipitating withdrawal and pain crisis). Repeat every 2–3 minutes up to 10 mg total if no response (consider non-opioid cause). For fentanyl overdose, standard doses may be insufficient — higher doses or infusion required. Infusion rate: two-thirds of effective bolus dose per hour. Duration: most opioids outlast naloxone — monitor for re-narcotization and redose PRN. Public access: intranasal naloxone (Narcan) and auto-injector (Evzio) are available OTC. Precipitated withdrawal: safe to induce but uncomfortable — nausea, vomiting, agitation.