Overview
Naloxone is an opioid antagonist used to rapidly reverse opioid-induced respiratory depression and central nervous system depression in cases of opioid overdose. It competitively binds to opioid receptors, displacing opioids and restoring normal respiratory function. It is considered a critical emergency medication for opioid overdose situations.
Mechanism of Action
Naloxone is a competitive opioid receptor antagonist with high affinity for mu-opioid receptors. It displaces opioid agonists from receptor sites without activating them, rapidly reversing opioid effects including respiratory depression, sedation, and hypotension.
Indications
- Complete or partial reversal of opioid-induced respiratory depression
- Diagnosis of suspected acute opioid overdose
- Reversal of postoperative opioid depression
- Adjunctive agent to increase blood pressure in septic shock management
Common Doses
- 0.4 mg/mL
- 1 mg/mL
- 2 mg/2 mL
- 4 mg/10 mL
Dosage
Administered intravenously, intramuscularly, or subcutaneously. For opioid overdose: initial IV dose 0.4-2 mg, repeat every 2-3 minutes as needed. Pediatric dose: 0.01 mg/kg IV initially. Postoperative opioid depression: titrate with smaller doses (0.1-0.2 mg IV increments).
Contraindications
- Hypersensitivity to naloxone hydrochloride or any formulation ingredients
Side Effects
- Nausea, vomiting, sweating, tachycardia
- Hypertension, hypotension, ventricular arrhythmias
- Pulmonary edema, cardiac arrest
- Agitation, tremulousness, seizures
- Opioid withdrawal symptoms in dependent patients
Interactions
- Large doses required to antagonize buprenorphine due to its slow receptor dissociation
- Methohexital may block naloxone-induced withdrawal symptoms in opioid addicts
Counseling Points
- Administer immediately for suspected opioid overdose
- Multiple doses may be needed as effects may wear off before opioids
- Monitor for return of respiratory depression
- May cause acute withdrawal in opioid-dependent individuals
- Seek emergency medical care even after administration