Hypercalcemia is treated with which of the following as initial therapy?

Hypercalcemia is treated with which of the following as initial therapy?

• A. Oral calcium supplements
• B. IV isotonic saline and IV furosemide
• C. Calcitonin only
• D. Plicamycin

Answer: (B)

The key idea is that the first step in treating hypercalcemia is to restore circulating volume and promote calcium excretion. Starting with vigorous IV isotonic saline rehydrates the patient, expands intravascular volume, and improves kidney perfusion, which raises the glomerular filtration rate and helps the kidneys excrete calcium. After hydration is established, adding a loop diuretic like furosemide further increases calcium loss in the urine, accelerating the drop in serum calcium. This combination directly targets the underlying problem—impaired calcium clearance due to dehydration and high calcium load—and provides a rapid, practical way to lower calcium levels. Oral calcium supplements would worsen the situation, so they’re not used. Calcitonin can lower calcium quickly but its effect is modest and short-lived due to tachyphylaxis, so it’s typically an adjunct rather than the primary initial therapy. Plicamycin (mithramycin) can lower calcium but is toxic and reserved for refractory cases, not as initial treatment.

The key idea is that the first step in treating hypercalcemia is to restore circulating volume and promote calcium excretion. Starting with vigorous IV isotonic saline rehydrates the patient, expands intravascular volume, and improves kidney perfusion, which raises the glomerular filtration rate and helps the kidneys excrete calcium. After hydration is established, adding a loop diuretic like furosemide further increases calcium loss in the urine, accelerating the drop in serum calcium. This combination directly targets the underlying problem—impaired calcium clearance due to dehydration and high calcium load—and provides a rapid, practical way to lower calcium levels.

Oral calcium supplements would worsen the situation, so they’re not used. Calcitonin can lower calcium quickly but its effect is modest and short-lived due to tachyphylaxis, so it’s typically an adjunct rather than the primary initial therapy. Plicamycin (mithramycin) can lower calcium but is toxic and reserved for refractory cases, not as initial treatment.