Which of the following cells most likely represent the main site of action of octreotide in a patient with acromegaly?

Correct Answer: B

Rationale: The correct answer is B: Pituitary somatotrophs. Octreotide is a somatostatin analog that inhibits the release of growth hormone. Somatotrophs in the pituitary gland are the cells responsible for producing and releasing growth hormone. By acting on these cells, octreotide can effectively reduce the elevated levels of growth hormone seen in acromegaly. Supraoptic neurons (A) are responsible for producing and releasing vasopressin, not growth hormone. Pituitary thyrotrophs (C) produce and release thyroid-stimulating hormone, not growth hormone. Paraventricular neurons (D) are involved in regulating oxytocin release, not growth hormone. Therefore, the main site of action of octreotide in acromegaly is on pituitary somatotrophs.

Correct Answer: A

Rationale: Step-by-step rationale for the correct answer (A: Pegvisomant): 1. Patient likely has acromegaly due to elevated growth hormone levels. 2. Pegvisomant is a growth hormone receptor antagonist used to treat acromegaly by blocking the effects of growth hormone. 3. This drug would be appropriate to normalize the patient's growth hormone levels and improve symptoms. Summary of why other choices are incorrect: - B: Degarelix is a gonadotropin-releasing hormone antagonist used in prostate cancer, not for acromegaly. - C: Leuprolide is a gonadotropin-releasing hormone agonist used in various conditions like prostate cancer and endometriosis, not for acromegaly. - D: Cosyntropin is a synthetic form of adrenocorticotropic hormone used in diagnostic testing for adrenal function, not for acromegaly treatment.

Correct Answer: C

Rationale: The correct answer is C: Methimazole. Methimazole is an antithyroid drug used to treat hyperthyroidism by inhibiting thyroid hormone synthesis. The results described are likely due to hyperthyroidism, which methimazole would help regulate. Radioactive iodine (A) is used to destroy thyroid tissue, potassium iodide (B) is used to protect the thyroid from radiation, and propranolol (D) is a beta-blocker used to manage symptoms but does not directly address thyroid hormone levels.

Correct Answer: B

Rationale: The correct answer is B: Sweating. Excessive dose of methimazole, an anti-thyroid medication used to treat Graves disease, can lead to increased sympathetic nervous system activity, causing hyperactivity of sweat glands and resulting in sweating. Palpitations (A) are more commonly associated with hyperthyroidism itself, rather than medication side effects. Insomnia (C) can be a symptom of hyperthyroidism but is not a direct effect of methimazole overdose. Tremor (D) is also a common symptom of hyperthyroidism, not a specific effect of methimazole overdose.

Correct Answer: A

Rationale: The correct answer is A: Prednisone. Prednisone is a corticosteroid that can cause signs and symptoms such as weight gain, fluid retention, and mood changes, which align with the patient's presentation. Mesalamine (B) is used to treat inflammatory bowel disease and does not typically cause these symptoms. Loperamide (C) is an anti-diarrheal agent and would not explain the patient's signs. Azathioprine (D) is an immunosuppressant used in inflammatory conditions but is less likely to cause the specific signs and symptoms described.