Naloxone
Narcan · Kloxxado
Opioid Receptor AntagonistGeneric available
Naloxone is a competitive antagonist at opioid receptors (primarily mu-opioid) with high affinity and selectivity. Antagonizes opioid effects including respiratory depression, sedation, hypotension, and can reverse psychotomimetic/dysphoric effects of agonist-antagonists (pentazocine). Onset rapid IV (2 minutes); intranasal slower but suitable for emergency use. Duration short (~1-2 hours) — shorter than most opioids, requiring repeat dosing and continuous surveillance.
Compare Naloxone →FDA-Approved Indications
- Emergency treatment of known or suspected opioid overdose manifested by respiratory and/or CNS depression
What Sets This Drug Apart
- Opioid antagonist — NOT psychiatric drug but critical for opioid overdose emergency reversal
- Very short duration (~1-2 hours) vs most opioids — repeat dosing every 2-3 minutes required; relapse into respiratory depression common
- Non-invasive nasal spray formulation (4 mg) suitable for emergency use outside hospital settings
- PRECIPITATES SEVERE OPIOID WITHDRAWAL in dependent patients — may be life-threatening in neonates; life-threatening in adults if not managed
- Cardiovascular risks in postoperative/cardiac patients — abrupt reversal may cause hypertension, tachycardia, arrhythmias, pulmonary edema, cardiac arrest
- Limited efficacy with partial agonists (buprenorphine, pentazocine) — may require higher/repeated doses