1. Which of the following mechanisms is responsible for the adverse effects of opioids on the respiratory system? A. Stimulation of mu receptors in the brainstem B. Inhibition of the release of acetylcholine C. Activation of kappa receptors in the lungs D. Blockade of beta-adrenergic receptors in the diaphragm Answer: A. Stimulation of mu receptors in the brainstem Rationale: Opioids exert their respiratory depressant effects primarily through stimulation of mu receptors in the brainstem, leading to decreased respiratory drive. 2. What is the antidote for opioid overdose that blocks the effects of opioids at the receptor level? A. Naloxone B. Flumazenil C. Atropine D. Epinephrine Answer: A. Naloxone Rationale: Naloxone is a competitive antagonist at opioid receptors and is the antidote of choice for opioid overdose. 3. Which of the following opioids is the most likely to cause a prolonged QT interval and torsades de pointes? A. Fentanyl B. Methadone C. Morphine D. Hydrocodone Answer: B. Methadone Rationale: Methadone has been associated with prolonged QT intervals and torsades de pointes due to its effects on cardiac ion channels. 4. Which of the following symptoms is characteristic of opioid overdose? A. Tachycardia B. Hypertension C. Pinpoint pupils D. Agitation Answer: C. Pinpoint pupils