Which of the following events best explains the patient's syndrome of weakness, paresthesias, constipation, and low potassium level in Addison disease?

Correct Answer: B

Rationale: The correct answer is B: Fludrocortisone excess. In Addison's disease, there is adrenal insufficiency leading to low levels of cortisol and aldosterone. Fludrocortisone is a synthetic mineralocorticoid used to replace aldosterone in the treatment of Addison's disease. Excess fludrocortisone can cause retention of sodium and water, leading to hypertension, hypokalemia, weakness, and paresthesias. Constipation can also occur due to altered electrolyte balance. A: Cortisol-induced hyperglycemia is not the best explanation for the patient's symptoms as hyperglycemia is not a prominent feature of Addison's disease. C: Inadequate therapy of adrenal insufficiency would not cause the specific symptoms mentioned. D: Cortisol-induced myopathy is not the primary cause of weakness and paresthesias in Addison's disease; aldosterone deficiency leading to electrolyte imbalance is more relevant.

Correct Answer: B

Rationale: The correct answer is B: Oxandrolone. Oxandrolone is an anabolic steroid known to cause hyperpigmentation due to increased melanin production. The patient's history of taking oxandrolone aligns with the presentation of hyperpigmentation on her face. Ethinyl estradiol (choice A) is a common component of hormonal contraceptives but is not known to cause hyperpigmentation. Erythropoietin (choice C) is a hormone used to stimulate red blood cell production and is not associated with hyperpigmentation. Norethindrone (choice D) is another hormonal contraceptive component that does not typically cause hyperpigmentation. In this case, the patient's use of oxandrolone is the most likely culprit for her hyperpigmentation.

Correct Answer: A

Rationale: Step 1: Cholecalciferol is the inactive form of vitamin D, which is converted to calcitriol in the body. Step 2: In a patient with vitamin D deficiency due to inadequate intake, supplementing with cholecalciferol is necessary to raise vitamin D levels. Step 3: Calcitriol (choice B) is the active form of vitamin D and is not the first-line treatment for deficiency due to inadequate intake. Step 4: Teriparatide (choice C) is a medication used for osteoporosis, not for treating vitamin D deficiency. Step 5: Cinacalcet (choice D) is used for treating hyperparathyroidism, not for vitamin D deficiency. Summary: Cholecalciferol is the appropriate choice as it directly addresses the deficiency by providing the precursor to active vitamin D, while the other choices are not indicated for this specific situation.

Correct Answer: C

Rationale: The correct answer is C: Pamidronate. This drug is used in the management of conditions like hypercalcemia, Paget's disease, and osteoporosis, which are commonly associated with cancer patients. It inhibits bone resorption and helps lower calcium levels. Sodium phosphate (A) is a laxative, not indicated for this patient. Hydrochlorothiazide (B) is a diuretic used for hypertension, not for managing the conditions mentioned. Mannitol (D) is an osmotic diuretic mainly used for reducing intracranial pressure, not indicated in this case. Pamidronate is the best choice due to its mechanism of action and relevance to the patient's condition.

Correct Answer: C

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