Naloxone (Narcan) is best described as which type of drug?

• A. An opioid antagonist
• B. An opioid agonist
• C. A sedative
• D. A stimulant

Answer: (B)

Naloxone acts by blocking opioid receptors in the brain, specifically acting as an antagonist at mu receptors. It binds with high affinity and displaces opioid molecules, reversing the effects of opioid overdose without producing opioid effects of its own. This makes it fundamentally different from an opioid agonist, which would activate receptors and cause opioid-like effects. It’s not a sedative or a stimulant either—the drug’s purpose is to block the action of opioids, not to depress or stimulate the central nervous system. In clinical use, naloxone rapidly reverses life-threatening respiratory depression from opioids, though its effects can wear off before some opioids do, so monitoring and possible repeat dosing are important.