Calcium carbonate antacids may contribute to constipation; in which patient populations should use be approached with caution?

• A. Hypercalcemia, kidney stones, or significant renal impairment
• B. Hyperkalemia
• C. Hypertension
• D. Liver disease

Answer: (A)

Calcium-containing antacids can raise calcium levels in the body and slow intestinal movement, which explains why constipation is a common side effect. Because these products deliver calcium, they can worsen high calcium levels (hypercalcemia) and contribute to the formation of calcium-containing kidney stones. In people with significant renal impairment, the kidneys struggle to excrete the extra calcium, increasing the risk of hypercalcemia and related issues like milk-alkali syndrome. For these reasons, use should be approached with caution in patients with hypercalcemia, a history of kidney stones, or substantial kidney dysfunction.

The other conditions listed don’t directly frame the same distinct risks with calcium-based antacids: hyperkalemia, hypertension, and liver disease aren’t primarily driven by calcium load or renal calcium handling in this context.