A nurse is caring for a postoperative client who is receiving fentanyl. Which of the following medications should the nurse plan to administer to the client if manifestations of fentanyl toxicity occur?.

Choice A rationale: Flumazenil is used to reverse the effects of benzodiazepines, not opioids like fentanyl. Choice B rationale: Naloxone is an opioid antagonist that can quickly reverse an opioid overdose, including fentanyl. Choice C rationale: Protamine is used to reverse the effects of heparin, a blood thinner, not opioids. Choice D rationale: Atropine is used to treat bradycardia and symptoms of nerve gas exposure, not opioid toxicity.