Question of the Day
Study for the USMLE Step 2, daily.
USMLE Step 2 Question of the Day
A 43-year-old female presents with bone pain, joint pain, and fatigue. Further history reveals blood in her urine and difficulty with bowel movements. She denies recent weight loss, poor appetite, and night sweats. She has no chronic medical conditions and does not take any medications or use drugs. Her family history is negative for malignancy. Physical examination is negative for lymphadenopathy or hepatosplenomegaly. Laboratory values reveal serum calcium 11.2 mg/dL, serum phosphorous 2.0 mg/dL, urine calcium 410 mg, and increased levels of serum 1,25-hydroxyvitamin D and parathyroid hormone. Which of the following medications can most likely help in treating this patient?
Correct Answer:
Explanation:
This patient presents with signs of hypercalcemia or “stones, bones, groans, moans, and overtones.” These include kidney stones, nephrocalcinosis, thirst, polyuria, bone pain with possible fractures, anorexia, dyspepsia, constipation, fatigue, myalgia, proximal muscle weakness, joint pain, depression, memory loss, confusion, lethargy, and coma. Several etiologies may result in hypercalcemia, including primary hyperparathyroidism, multiple endocrine neoplasia syndromes, exogenous vitamin D administration, and malignancy. In primary hyperparathyroidism, serum calcium, 1,25-hydroxyvitamin D, and parathyroid hormone are elevated while serum phosphorous is low. Urine calcium is also elevated.
Furosemide (Choice C) is a loop diuretic that inhibits the cotransport of Na+/K+/2Cl- in the ascending limb of the loop of Henle, thus decreasing reabsorption and increasing excretion of calcium and 1,25-hydroxyvitamin.
1,25-hydroxyvitamin (Choice A), or Vitamin D, is used as a treatment for hypocalcemia. It increases intestinal calcium and phosphate absorption while decreasing renal excretion, thus increasing the blood levels of both ions.
Calcium gluconate (Choice B) is used as a treatment for hypocalcemia. It would be contraindicated in this case as the patient’s serum calcium is already high.
Hydrochlorothiazide (Choice D) is a thiazide diuretic that can be used as a treatment for hypocalcemia. In contrast to furosemide, it promotes the reabsorption of calcium to decrease the calcium content of urine.
Magnesium sulfate (Choice E) is used as a treatment for hypomagnesemia, which is often associated with hypocalcemia.
Quick Concepts:
Furosemide ion effects
– Decreases serum calcium levels
– Decreases serum potassium levels
– Decreases serum magnesium levels
Summary:
Furosemide can decrease serum calcium levels. It can also decrease serum potassium and magnesium levels.
Correct Answer:
Explanation:
This patient presents with signs of hypercalcemia or “stones, bones, groans, moans, and overtones.” These include kidney stones, nephrocalcinosis, thirst, polyuria, bone pain with possible fractures, anorexia, dyspepsia, constipation, fatigue, myalgia, proximal muscle weakness, joint pain, depression, memory loss, confusion, lethargy, and coma. Several etiologies may result in hypercalcemia, including primary hyperparathyroidism, multiple endocrine neoplasia syndromes, exogenous vitamin D administration, and malignancy. In primary hyperparathyroidism, serum calcium, 1,25-hydroxyvitamin D, and parathyroid hormone are elevated while serum phosphorous is low. Urine calcium is also elevated.
Furosemide (Choice C) is a loop diuretic that inhibits the cotransport of Na+/K+/2Cl- in the ascending limb of the loop of Henle, thus decreasing reabsorption and increasing excretion of calcium and 1,25-hydroxyvitamin.
1,25-hydroxyvitamin (Choice A), or Vitamin D, is used as a treatment for hypocalcemia. It increases intestinal calcium and phosphate absorption while decreasing renal excretion, thus increasing the blood levels of both ions.
Calcium gluconate (Choice B) is used as a treatment for hypocalcemia. It would be contraindicated in this case as the patient’s serum calcium is already high.
Hydrochlorothiazide (Choice D) is a thiazide diuretic that can be used as a treatment for hypocalcemia. In contrast to furosemide, it promotes the reabsorption of calcium to decrease the calcium content of urine.
Magnesium sulfate (Choice E) is used as a treatment for hypomagnesemia, which is often associated with hypocalcemia.
Quick Concepts:
Furosemide ion effects
– Decreases serum calcium levels
– Decreases serum potassium levels
– Decreases serum magnesium levels
Summary:
Furosemide can decrease serum calcium levels. It can also decrease serum potassium and magnesium levels.