Which of the following agent was first introduced for treatment of epilepsy

Correct Answer: B

Rationale: The correct answer is B: Phenobarbital. Phenobarbital was the first agent introduced for the treatment of epilepsy in the early 1900s. It was discovered to have anticonvulsant properties and became a mainstay in epilepsy treatment. Phenytoin (A), Carbamazepine (C), and Valproic acid (D) were introduced later than Phenobarbital and are not the first agents used for epilepsy treatment. Therefore, the correct answer is Phenobarbital as it was the first agent specifically developed and used for epilepsy treatment.

Correct Answer: A

Rationale: The correct answer is A because buprenorphine is a partial agonist at the Mu receptor. This means it can activate the receptor but with less efficacy compared to a full agonist, resulting in a ceiling effect and lower risk of respiratory depression. Choice B is incorrect because buprenorphine is not a full agonist at the Mu receptor. Choices C and D are incorrect as buprenorphine primarily acts on the Mu receptor, not the K receptor.

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: Bradykinin is a peptide that causes vasodilation, pain, and an increase in vascular permeability. However, it does not directly cause bronchodilation. This is because bradykinin primarily acts on blood vessels and capillaries, leading to increased blood flow and leakage of fluids, but it does not have a direct effect on the smooth muscle of the bronchioles. Therefore, the correct answer is A. Vasodilation, not bronchodilation. Choices B, C, and D are incorrect because they are all known actions of bradykinin based on its physiological effects.

Correct Answer: A

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