Slow reacting substance of anaphylaxis

Correct Answer: C

Rationale: The correct answer is C: LTC4. Slow reacting substance of anaphylaxis (SRS-A) is a leukotriene, with LTC4 being the initial form. It plays a key role in allergic reactions by causing bronchoconstriction and increased vascular permeability. PGD2, TXA2, and PGI are not classified as slow reacting substances of anaphylaxis and do not have the same physiological effects as LTC4.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: The correct answer is C (Both). Serotonin agonists like buspirone are used as anxiolytics by acting on serotonin receptors. Sumatriptan is used for migraines by constricting blood vessels and blocking pain pathways. Therefore, both options A and B are correct. Option D is incorrect because both buspirone and sumatriptan have clinical uses as serotonin agonists.

Correct Answer: D

Rationale: CNS stimulant agents belong to multiple categories, including respiratory stimulants that increase breathing, psychomotor stimulants that enhance physical activity, and psychomimetic agents that induce hallucinations or altered perceptions. Therefore, the correct answer is D, "All of the above," as CNS stimulants can have effects on various functions in the central nervous system. Choices A, B, and C are incorrect because CNS stimulants do not exclusively belong to any single category, but rather have a broad range of effects on different aspects of brain function.

Correct Answer: A

Rationale: Rationale: Carbamazepine is chemically derived from the tricyclic antidepressant imipramine. It is commonly used as an anti-epileptic medication. Carbamazepine's mechanism of action involves blocking voltage-gated sodium channels in neurons. This helps to stabilize the hyperexcitable neuronal membranes in epilepsy. Ethosuximide and Phenytoin are not derived from tricyclic antidepressants and have different mechanisms of action in treating epilepsy. Therefore, the correct answer is A: Carbamazepine.