解毒劑 Opioid overdose
1. Reversal of opioid depression (including respiratory depression) induced by natural and synthetic opioids (eg, propoxyphene, methadone, nalbuphine, butorphanol, pentazocine)
2. Diagnosis of suspected or known acute opioid overdosage

Antidote; Opioid Antagonist
Naloxone, an N-allyl derivative of oxymorphone, is a pure narcotic antagonist that competitively binds at opiate receptors. It is used to reverse the effect of narcotic agonists and drugs with partial agonist properties.

1. Onset of action: 2 to 5 minutes
2. Duration: ~30 to 120 minutes depending on route of administration; IV has a shorter duration of action than IM administration; since naloxone's action is shorter than that of most opioids, repeated doses are usually needed
3. Protein binding: Relatively weak (to albumin [major] and other plasma constituents)
4. Metabolism: Primarily hepatic via glucuronidation
5. Half-life elimination: (Neonates) Mean 3.1 ± 0.5 hours; (Adults) 0.5 to 1.5 hours; (Intranasal) ~2 hours
6. Time to peak: 15 minutes
7. Excretion: Urine (as metabolites)

Hypersensitivity to naloxone or any component of the formulation

1. Although naloxone may precipitate opioid withdrawal in the fetus in addition to the mother, treatment should not be withheld when needed in cases of maternal opioid overdose.
2. When using the injection, starting at the low end of the dosing range is suggested to help avoid adverse fetal events.
3. Use of naloxone to test for opioid dependence during pregnancy is not recommended.

According to the manufacturer, the decision to continue or discontinue breastfeeding during therapy should consider the risk and the benefits.

Nausea, vomiting, sweating, tachycardia, hypertension, tremulousness

Opioid overdose: (IV, IM)
1. Initial 0.4 to 2 mg, may need to repeat doses every 2 to 3 minutes; a lower initial dose (0.1 to 0.2 mg) should be considered for patients with opioid dependence to avoid acute withdrawal or if there are concerns regarding concurrent stimulant overdose.
2. After reversal, may need to readminister dose(s) at a later interval (ie, 20 to 60 minutes) depending on type/duration of opioid. If no response is observed after 10 mg total, consider other causes of respiratory depression.
Reversal of respiratory depression with therapeutic opioid doses (Postoperative): (IV)
0.1 to 0.2 mg every 2 to 3 minutes until desired response (adequate ventilation and alertness without significant pain); Repeat doses may be needed within 1 to 2 hour intervals depending on type, dose, and timing of the last dose of opioid administered

Opioid intoxication/overdose (full reversal): (Prefer IV)
1. Infants and Children <5 years or ≤20 kg: 0.1 mg/kg/dose; repeat every 2 to 3 minutes if needed; may need to repeat doses (eg, every 20 to 60 minutes) if duration of action of opioid is longer than naloxone
2. Children ≥5 years or >20 kg and Adolescents: 2 mg/dose; if no response, repeat every 2 to 3 minutes; may need to repeat doses (eg, every 20 to 60 minutes) if duration of action of opioid is longer than naloxone

There are no dosage adjustments provided in the manufacturer's labeling.

There are no dosage adjustments provided in the manufacturer's labeling.