Opioid Pharmacology and Toxicity

A 42-year-old man with chronic pain from metastatic cancer is on morphine 60 mg/day. He presents to the emergency department with severe respiratory depression (RR 8/min), pinpoint pupils, and altered mental status. His wife reports he took an extra dose 2 hours ago. Arterial blood gas shows pH 7.20, PaCO₂ 85 mmHg, PaO₂ 55 mmHg. What is the immediate pharmacological intervention?

A 42-year-old woman on chronic opioid therapy for cancer pain develops acute chest pain, dyspnea, and hypotension 30 minutes after receiving a bolus of intravenous morphine. Cardiac auscultation reveals no new murmurs. Which investigation is most specific for diagnosing opioid-induced anaphylactoid reaction (non-IgE-mediated mast cell degranulation)?

During a postoperative audit of opioid-related adverse events in your hospital, the most common cause of acute opioid-induced respiratory depression in the recovery room is identified. Which of the following is the most frequent culprit?

A 52-year-old man with chronic pain on long-term morphine therapy presents to the emergency department with altered mental status, pinpoint pupils, and severe respiratory depression (RR 6/min, SpO₂ 78%). After securing the airway and initiating bag-mask ventilation, naloxone is administered intravenously. Which of the following statements regarding opioid toxicity and naloxone management is INCORRECT?

Which feature best distinguishes morphine from fentanyl in terms of clinical pharmacokinetics and organ dependence?