Postoperative patients who received opioids may require which antidote?

• A. Naloxone (Narcan)
• B. Flumazenil
• C. Protamine sulfate
• D. Vitamin K

Answer: (A)

Opioid overdose or opioid-induced respiratory depression after surgery is treated by reversing the opioid’s effects at the brain’s receptors. Naloxone is a competitive opioid antagonist that binds to mu receptors more readily than the opioid, displacing it and rapidly reversing sedation and compromised breathing. This makes it the antidote of choice for postoperative patients who received opioids when there’s risk of life-threatening respiratory depression or decreased consciousness.

Be mindful that naloxone’s effect can wear off before the opioid does, so patients must be closely monitored and may need repeat dosing or infusion to prevent re-narcotization. It can also precipitate withdrawal or cause sudden return of pain in those who are opioid-dependent, so dosing is titrated carefully.

Flumazenil reverses benzodiazepines, not opioids. Protamine sulfate reverses heparin, and vitamin K reverses warfarin’s anticoagulant effects.