Correct statements about adrenocorticotropic hormone (ACTH) include all of the following EXCEPT:

Correct Answer: D

Rationale: The correct answer is D. The oral route is not the preferred method of administering ACTH because it has poor oral bioavailability. ACTH is typically administered parenterally. A: True, endogenous ACTH is also known as corticotropin. B: Correct, ACTH stimulates corticosteroid synthesis. C: True, ACTH is clinically useful in diagnosing adrenal insufficiency. Therefore, choice D is incorrect due to poor oral bioavailability compared to parenteral routes.

Correct Answer: A

Rationale: The correct answer is A: Piroxicam. Piroxicam is a nonselective COX inhibitor because it inhibits both COX-1 and COX-2 enzymes. This makes it effective for reducing inflammation by blocking prostaglandin synthesis. Rofecoxib (B) is a selective COX-2 inhibitor, while Celecoxib (C) is also a selective COX-2 inhibitor. Therefore, choices B and C are incorrect. Choice D is incorrect as well because not all listed NSAIDs are nonselective COX inhibitors.

Correct Answer: C

Rationale: The correct answer is C: Immunosuppressive agents. Sirolimus belongs to the class of immunosuppressive agents because it inhibits the activity of T-lymphocytes and prevents rejection of transplanted organs. It does not belong to the classes of A: Immunoglobulins, B: Interferons, or D: Monoclonal antibodies, as these are not mechanisms of action associated with sirolimus. Immunoglobulins are antibodies, interferons are signaling proteins, and monoclonal antibodies are targeted therapies. Therefore, the most appropriate classification for sirolimus is as an immunosuppressive agent.

Correct Answer: B

Rationale: The correct answer is B: Vitamin BC, also known as folic acid. Folic acid improves megaloblastic anemia by aiding in DNA synthesis. It does not protect against neurological manifestations of pernicious anemia because those are primarily caused by Vitamin B12 deficiency. Vitamin B12 is needed for nerve function and myelin synthesis. Vitamin PP refers to niacin, which is not directly related to these types of anemia. Vitamin D is important for bone health but is not directly involved in the treatment of megaloblastic anemia or pernicious anemia.

Correct Answer: B

Rationale: The correct answer is B: FALSE. Bile acid-binding resins work by binding bile acids in the intestine, not cholesterol directly. This binding leads to increased excretion of bile acids in feces and stimulates the liver to use more cholesterol to produce new bile acids, thus lowering blood cholesterol levels. Choice A is incorrect because bile acid-binding resins do not directly bind cholesterol. Choices C and D are incorrect as they do not accurately reflect the mechanism of action of bile acid-binding resins.