The greatest threat from morphine poisoning is

Correct Answer: C

Rationale: In the context of pharmacology of CNS drugs, understanding the effects and potential risks associated with morphine poisoning is crucial. The correct answer is C) Respiratory depression. Morphine, being an opioid, primarily affects the central nervous system. One of the most significant dangers of morphine poisoning is its ability to suppress the respiratory center in the brainstem, leading to shallow breathing or even respiratory arrest. This is a life-threatening complication that can result in hypoxia and ultimately death if not promptly addressed. Option A) Renal shutdown is incorrect because morphine does not directly impact renal function to the extent that it poses the greatest threat in cases of poisoning. Option B) Paralysis of the spinal cord is not a typical manifestation of morphine poisoning and is not the primary concern in this scenario. Option D) Cardiovascular collapse, while a potential complication of severe opioid overdose, is not as immediate and directly life-threatening as respiratory depression in the context of morphine poisoning. Educationally, this question highlights the importance of recognizing the specific effects of CNS drugs like morphine and understanding the priority interventions in cases of overdose. It underscores the critical role of healthcare providers in monitoring for and managing respiratory depression in patients receiving opioid therapy.

Correct Answer: D

Rationale: In the context of a comatose patient suspected of poisoning, the finding that would rule out morphine poisoning is the presence of Tranylcypromine. Tranylcypromine is a monoamine oxidase inhibitor (MAOI) used in the treatment of depression and is not associated with opioid poisoning like morphine. A) Selegiline is also an MAOI but is used in the treatment of Parkinson's disease and depression. It would not rule out morphine poisoning. B) Moclobemide is a reversible MAOI used to treat depression. It is not relevant to ruling out morphine poisoning. C) Chlorgiline is another MAOI, but it is not commonly used and is not relevant to the scenario of ruling out morphine poisoning. Understanding the pharmacology of CNS drugs is crucial in clinical practice, especially in cases of poisoning where quick and accurate identification of the toxic agent is vital for appropriate management. This question highlights the importance of differentiating between different classes of drugs and their respective effects on the central nervous system to provide optimal patient care.

Correct Answer: D

Rationale: The correct answer to the question, "Which action of morphine is incompletely reversed by naloxone?" is D) Miosis. Morphine, an opioid analgesic, produces miosis (pupillary constriction) through its action on the parasympathetic nervous system. Naloxone is a competitive opioid receptor antagonist that can reverse many of the effects of opioids, such as analgesia, respiratory depression, and sedation, by displacing the opioid from its receptor. However, miosis caused by opioids is incompletely reversed by naloxone due to the involvement of other neurotransmitter systems in the regulation of pupillary size. Option A) Analgesia is reversed by naloxone as it competes with morphine for opioid receptors in the central nervous system, blocking its analgesic effects. Option B) Respiratory depression is reversed by naloxone as it displaces opioids from their receptors in the brainstem respiratory centers, restoring normal respiratory function. Option C) Sedation is reversed by naloxone as it antagonizes the effects of opioids on the central nervous system, leading to increased alertness and arousal. In an educational context, understanding the pharmacological actions and interactions of drugs like morphine and naloxone is crucial for healthcare professionals, particularly those working in settings where opioid overdose is a concern. Knowing the specific effects that can and cannot be reversed by naloxone is essential for providing timely and effective interventions in cases of opioid toxicity.

Correct Answer: A

Rationale: In the context of limiting cerebral edema due to a brain tumor, the preferred corticosteroids are betamethasone/dexamethasone because they do not cause Na+ and water retention, making option A the correct answer. Corticosteroids like prednisone can lead to sodium and water retention, which can exacerbate edema. Betamethasone and dexamethasone are more selective for glucocorticoid receptors and have less mineralocorticoid activity, reducing the risk of fluid retention. Option B is incorrect because potency is not the primary factor in this scenario; the focus is on the side effect profile. Option C is also incorrect as both betamethasone and dexamethasone can be administered intravenously. Option D is incorrect as corticosteroids do not directly inhibit brain tumors but rather reduce edema and inflammation associated with them. In an educational context, understanding the pharmacological properties of different corticosteroids is crucial for selecting the most appropriate agent for specific clinical scenarios. This knowledge ensures optimal patient outcomes by minimizing side effects and maximizing therapeutic benefits. Understanding the rationale behind drug selection based on mechanisms of action and side effect profiles is essential for healthcare professionals involved in managing CNS conditions like cerebral edema due to brain tumors.

Correct Answer: D

Rationale: In the context of pharmacology of CNS drugs, the correct answer is D) Neuralgia. Opioid analgesics are preferred over aspirin-like analgesics in conditions of severe pain, such as neuralgia, due to their stronger analgesic properties and ability to modulate pain perception at the central nervous system level. Neuralgia is characterized by intense, shooting pain along a nerve pathway, which often requires potent analgesics for effective pain relief. Options A, B, and C are not the preferred choice for opioid analgesics because they involve conditions where aspirin-like analgesics, such as NSAIDs, are more commonly used. Acute gout (Option A) is typically treated with NSAIDs or colchicine, toothache (Option B) can be managed with NSAIDs, acetaminophen, or local anesthetics, and burns (Option C) are usually treated with topical analgesics and wound care. Understanding the appropriate selection of analgesics based on the underlying condition is crucial in pharmacology to ensure optimal pain management and patient outcomes. Educating healthcare professionals on these distinctions helps them make informed decisions regarding drug therapy, considering factors such as efficacy, safety, and patient-specific needs.