Which doses of Aspirin may be more effective in inhibiting Tromboxane A2?

Correct Answer: A

Rationale: The correct answer is A: Low. Low doses of Aspirin are more effective in inhibiting Thromboxane A2 because they irreversibly inhibit cyclooxygenase-1 in platelets, which is necessary for Thromboxane A2 synthesis. High doses can lead to non-specific inhibition of COX-1 and COX-2, which may cause side effects. Choice B is incorrect because high doses can lead to non-specific inhibition. Choice C is incorrect because high doses are not more effective. Choice D is incorrect as low doses are effective.

Correct Answer: A

Rationale: The correct answer is A: Propranolol. Propranolol is a non-selective beta-blocker that can cause bronchoconstriction in patients with asthma due to its beta-blocking effects on beta-2 receptors in the lungs. This can worsen asthma symptoms and potentially lead to an asthma attack. Clonidine (B), Enalapril (C), and Nifedipine (D) do not have direct effects on bronchial smooth muscle and are not contraindicated in patients with bronchial asthma.

Correct Answer: C

Rationale: The correct answer is C: Growth hormone (somatotropin GH). The anterior lobe of the pituitary gland produces growth hormone. This hormone regulates growth, metabolism, and body composition. Thyrotropin-releasing hormone (TRH) and Corticotropin-releasing hormone (CRH) are produced by the hypothalamus to stimulate the release of thyroid-stimulating hormone and adrenocorticotropic hormone, respectively. Growth hormone-releasing hormone (GHRH) is also produced by the hypothalamus to stimulate the release of growth hormone. Therefore, the correct answer is C as it directly originates from the anterior lobe of the pituitary gland, unlike the other options.

Correct Answer: B

Rationale: Step 1: Sulphonylureas can cause hypoglycemia, weight gain, and gastrointestinal issues. Step 2: Biguanides can cause gastrointestinal issues and lactic acidosis. Step 3: Biguanides have fewer side effects compared to sulphonylureas. Step 4: Therefore, the statement that side effects of sulphonylureas are less than biguanides is FALSE. Summary: Choice B is correct because biguanides have fewer side effects than sulphonylureas, making the statement false. Choices A, C, and D are incorrect because the statement is not true for all options.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Indomethacin is an indol derivative due to its chemical structure containing an indole ring. 2. Ibuprofen is a propionic acid derivative, not an indol derivative. 3. Meclofenamic acid is a fenamic acid derivative, not an indol derivative. 4. Diclofenac is an acetic acid derivative, not an indol derivative. Summary: B (Indomethacin) is the correct answer as it is the only option that is an indol derivative. A, C, and D are incorrect as they belong to different chemical classes.