Diamprit is an agonist of ______ receptors, except

Correct Answer: D

Rationale: In pharmacology, understanding the mechanism of action of drugs on specific receptors is crucial for effective clinical application. In this case, Diamprit being an agonist of all histamine receptors (H1, H2, and H3) is a vital concept to grasp. The correct answer is D) All of the above because Diamprit acts as an agonist on all three histamine receptor subtypes. Histamine receptors are classified into H1, H2, and H3 types based on their physiological functions and pharmacological responses. By activating these receptors, Diamprit can elicit specific responses in the central nervous system (CNS). Option A) H1 receptor, and Option B) H2 receptor, are incorrect because Diamprit does not selectively target only one type of histamine receptor. It has affinity for all histamine receptor subtypes. Option C) H3 receptor is also incorrect because Diamprit, as mentioned earlier, acts on H3 receptors as well. Educationally, this question reinforces the importance of understanding the selectivity and specificity of drug-receptor interactions. It highlights the need for students to grasp the diverse effects that drugs can have based on their receptor profiles. Understanding such nuances is essential for safe and effective pharmacological interventions in clinical practice.

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: C

Rationale: In pharmacology, corticosteroids are a class of drugs commonly used for their potent anti-inflammatory effects. The correct answer to the question is option C) Phospholipase A. Corticosteroids exert their anti-inflammatory action by inhibiting phospholipase A2, an enzyme responsible for the release of arachidonic acid from cell membranes. Arachidonic acid is a precursor for the synthesis of inflammatory mediators such as prostaglandins and leukotrienes. Option A) Cyclooxygenase is the target of nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen, not corticosteroids. Cyclooxygenase is involved in the synthesis of prostaglandins. Option B) Lipoxygenase is involved in the synthesis of leukotrienes, another group of inflammatory mediators, but it is not the target of corticosteroids. Option D) Phosphodiesterase is an enzyme that regulates the levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in the cell. Inhibition of phosphodiesterase is a mechanism of action for drugs like phosphodiesterase inhibitors used in conditions like erectile dysfunction and pulmonary hypertension. Understanding the mechanism of action of corticosteroids in inhibiting phospholipase A2 is crucial for healthcare professionals prescribing these drugs to manage inflammatory conditions such as asthma, rheumatoid arthritis, and inflammatory skin conditions. By knowing this mechanism, healthcare providers can better predict the therapeutic effects and potential side effects of corticosteroid therapy, leading to improved patient outcomes.

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.