What term best describes respiratory depression?

• A. Increased breathing
• B. Slowed or stopped breathing caused by opioids
• C. Normal breathing
• D. Irregular heartbeat

Answer: (B)

Respiratory depression refers to slowed or stopped breathing due to opioids. Opioids blunt the brainstem’s drive to breathe by activating mu receptors, reducing the body's responsiveness to carbon dioxide. This leads to a decreased breathing rate and shallower breaths, and can progress to hypoventilation or respiratory arrest if not addressed. It’s the dose-limiting adverse effect that underpins the careful monitoring required with opioid therapy and is a key reason naloxone is used to reverse overdose. By contrast, increased breathing would be stimulatory, normal breathing is simply baseline, and an irregular heartbeat points to a cardiac issue rather than a depression of respiratory drive.