The mechanism of action of antiseizure drugs is:

Correct Answer: D

Rationale: The correct answer is D. Antiseizure drugs work through multiple mechanisms to prevent seizures. 1. A: Antiseizure drugs enhance GABAergic transmission, increasing inhibition in the brain. 2. B: They also diminish excitatory glutamatergic transmission, reducing neuronal excitation. 3. C: Antiseizure drugs modify ionic conductance to stabilize neuronal activity. Therefore, the correct answer is D, as antiseizure drugs act through all the mentioned mechanisms to prevent seizures effectively. Choices A, B, and C are incorrect because they do not encompass the comprehensive range of mechanisms involved in the action of antiseizure drugs.

Correct Answer: C

Rationale: The correct answer is C: Fentanyl. Fentanyl is used in combination with droperidol in neuroleptanalgesia due to its fast onset of action and potent analgesic effects, making it an ideal choice for sedation and analgesia during procedures. Morphine (choice A) is not typically used in neuroleptanalgesia due to its slower onset of action and shorter duration. Buprenorphine (choice B) is a partial opioid agonist and is not commonly used in neuroleptanalgesia. Lastly, the duplicate choice D (Morphine) is incorrect for the same reasons mentioned earlier. In summary, Fentanyl is the preferred choice for neuroleptanalgesia due to its rapid onset and potent analgesic properties compared to the other options.

Correct Answer: A

Rationale: The correct answer is A: Agranulocytosis. Analgin can cause a serious side effect called agranulocytosis, which is a condition where the bone marrow stops producing enough white blood cells, leaving the body vulnerable to infections. This limits the usefulness of Analgin as the risk of developing agranulocytosis outweighs its benefits. Summary of other choices: B: Erosions and gastric bleeding - While Analgin can cause gastrointestinal side effects like erosions and bleeding, these are not as severe or limiting as agranulocytosis. C: Methemoglobinemia - Although Analgin can lead to methemoglobinemia, it is a rare side effect compared to agranulocytosis. D: Hearing impairment - There is no significant evidence linking Analgin to hearing impairment, making this choice incorrect.

Correct Answer: B

Rationale: The correct answer is B: Tranylcypramine. Tranylcypramine is an unselective MAO blocker, inhibiting both MAO-A and MAO-B, leading to long-lasting enzyme inhibition. Moclobemide (A) is a reversible MAO-A inhibitor. Selegiline (C) is a selective MAO-B inhibitor. Fluoxetine (D) is a selective serotonin reuptake inhibitor (SSRI) and does not inhibit MAO enzymes. Therefore, Tranylcypramine is the correct choice for producing long-lasting MAO inhibition.

Correct Answer: A

Rationale: The correct answer is A because caffeine actually stimulates gastric secretion, not inhibits it. Caffeine can increase stomach acid production, leading to potential digestive issues. Choices B, C, and D are incorrect because caffeine is known to cause hyperglycemia by increasing blood sugar levels, has a moderate diuretic action by increasing urine production, and increases free fatty acids in the bloodstream, which can affect metabolism. Therefore, based on its effects on gastric secretion, A is the correct answer.