Britannica Sources used in this answer

Why can an opioid overdose cause dangerous respiratory depression?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

How does the human body perceive and respond to pain? — pain Learn how the human body senses pain and reacts to it.

Opioids cause dangerous respiratory depression because they act on opioid receptors located within the central nervous system. While these receptors are involved in pain relief and euphoria, they are also present in areas of the brain and brainstem that regulate vital involuntary functions, including breathing.1234

When an individual takes an excessive dose of an opioid, the drug binds to these receptors and suppresses the neural pathways responsible for maintaining a normal respiratory rate. This inhibition of the brain's respiratory drive can lead to severe respiratory depression, which, if left untreated, results in respiratory failure and death.124

It is a fundamental ethical imperative to recognize the life-threatening nature of this physiological response. In medical emergencies, naloxone is used to reverse these effects by acting as a competitive antagonist, displacing the opioids from their receptors and restoring normal breathing.2