Naloxone
What is Naloxone?
A pure opioid antagonist used to reverse the effects of opioid overdose, including respiratory depression, sedation, and hypotension.
Mechanism of Action & Pharmacokinetics
Competitively binds to mu, delta, kappa, and sigma opioid receptors in the CNS, reversing or preventing opioid effects.Has a rapid onset of action within 1-2 minutes (IV) and a short duration of 30-60 minutes.
Metabolized in the liver and excreted through the kidneys.
Pharmacodynamics
Cardiovascular
Rapid reversal of opioids can cause hypertension, tachycardia, and even pulmonary edema or arrhythmias in severe cases.
Respiratory
Effectively reverses opioid-induced respiratory depression, restoring normal respiration.
Rapid administration can precipitate withdrawal symptoms in opioid-dependent individuals.
Indications
Reversal of opioid overdose, particularly in cases of respiratory depression.
Perioperative management of excessive sedation or respiratory depression due to opioids.
Dosage
Intravenous (IV):
Initial dose: 0.04 to 0.1 mg IV every 1-2 minutes to effect.
0.25-0.5 mcg/kg in pediatrics
Intramuscular (IM):
0.4 mg IM; may repeat as necessary.
Intranasal:
4 mg as a single spray in one nostril; may repeat as necessary.
IV Infusion:
Contraindications
Hypersensitivity to naloxone or any of its components.
Use with caution in opioid-dependent patients, as it may precipitate acute withdrawal symptoms.
Complications
Acute opioid withdrawal symptoms, including agitation, nausea, vomiting, tachycardia, and hypertension.
Risk of pulmonary edema, particularly in patients with pre-existing cardiac conditions.
Reversal of analgesia, leading to the return of pain.
References