A nurse is caring for a client who is postoperative and develops respiratory depression after receiving morphine for pain control. Which of the following medications should the nurse expect the provider to prescribe?

Rationale: A. Calcium gluconate: Calcium gluconate is administered to treat hypocalcemia, hyperkalemia with cardiac membrane instability, or calcium channel blocker toxicity. It stabilizes myocardial cell membranes but does not reverse the central nervous system or respiratory depressant effects of opioids. Morphine-induced respiratory depression results from mu-receptor activation in the brainstem, which is not affected by calcium administration. B. Naloxone: Naloxone is a competitive opioid antagonist that binds to mu-opioid receptors and displaces opioids such as morphine. By reversing receptor activation in the brainstem respiratory centers, it restores respiratory drive and improves ventilation. It is the standard treatment for opioid-induced respiratory depression. C. Flumazenil: Flumazenil is a benzodiazepine antagonist used to reverse sedation caused by medications such as midazolam or diazepam. It acts at gamma-aminobutyric acid (GABA) receptors rather than opioid receptors. Since morphine exerts its effects through opioid receptor pathways, flumazenil would not correct opioid induced respiratory depression. D. Diphenhydramine: Diphenhydramine is an antihistamine commonly used to treat allergic reactions or mild opioid-induced pruritus. It does not reverse opioid effects on the central nervous system or respiratory centers. Sedative properties of diphenhydramine could potentially worsen respiratory depression in a postoperative client.