What is the reversing agent for opioid-induced respiratory depression?

• A. Naloxone
• B. Romazicon
• C. Naltrexone
• D. Flumazenil

Answer: (A)

Opioid-induced respiratory depression is best treated by a drug that quickly blocks the opioid receptors, freeing the brainstem to resume normal breathing. Naloxone is a potent μ-opioid receptor antagonist. By occupying these receptors, it displaces opioids such as morphine, fentanyl, or heroin and rapidly reverses the depressant effects on respiration, often within minutes when given intravenously or intramuscularly.

A key practical point is that naloxone has a relatively short duration of action compared with many opioids, so breathing support should be continued and repeated doses or a drip may be needed to prevent re-narcotization as the opioid remains in the body. It can also precipitate withdrawal in people who are opioid dependent, so dosing must be titrated to effect with careful monitoring.

The other agents don’t fit this scenario: flumazenil reverses benzodiazepines, not opioids; naltrexone is an opioid antagonist used for long-term management and has a slower onset, not ideal for acute reversal; and Romazicon is an older name for flumazenil, again for benzodiazepines, not opioids.