Naloxone (Narcan)

Anesthesia Implications

Classification: Opioid antagonist
Therapeutic Effects: Opioid reversal
Time to Onset: IV: 1-2 minutes; IM: 2-5 minutes

Duration: 30-45 minutes

Primary Considerations

Epidural Opioids – small doses of naloxone can be given to reverse the adverse affects of epidural opioids without necessarily reversing the analgesia.

Sympathetic stimulation – rapid reversal of opioids can stimulate a sympathetic response (tachycardia, ventricular irritability, hypertension, and pulmonary edema). This is caused by acute pain that is no longer covered by opioids. This response is particularly severe in the opioid dependent.

Clonidine – Narcan may antagonize the antihypertensive affects of clonidine.

Rare complications – Pulmonary hypertension and pulmonary edema are the two most serious complications of narcan

IV push dose

Adult: 0.5–1 mcg/kg every 3–5 min, titrated to respiratory rate
(in a 10 ml syringe, draw up the 1 ml 0.4 mg/ml with 9 ml of saline. That makes 40 mcg/ml)

This drug will wear off well before the opioids, so follow with IM naloxone (1-2 mcg/kg) or an infusion (4-5 mcg/kg/hr)

Pediatric: Neonate less than 5 years of age or less than 20 kg of body weight: 0.1 mg/kg. This dose may be repeated as necessary.

5 years and older or body weight more than 20 kg: 2 mg by IV push, intraosseus or by ET tube. Follow each dose given via ET tube with at least 5 mL of isotonic sodium chloride injection

IV infusion dose

Adult: 4-5 mcg/kg/hr – this infusion is usually preceded by the IV bolus dose

IM dose

Adult: 1-2 mcg/kg – this dose is usually preceded by the IV bolus dose

Method of Action

Competitive opioid antagonist with a high affinity for the mu-opioid receptor

Metabolism

Hepatic

Elimination

Renal