Which ingredient in OTC antacids can accumulate with kidney disease and should be used with caution?

• A. Calcium carbonate
• B. Magnesium hydroxide
• C. Aluminum-containing compounds
• D. Sodium bicarbonate

Answer: (C)

In kidney disease, substances in OTC antacids that are cleared by the kidneys can build up in the body and cause toxicity. Aluminum-containing compounds are especially risky because aluminum tends to accumulate when renal clearance is impaired. Over time this aluminum deposition can lead to bone disorders such as osteomalacia and also neurotoxic effects like encephalopathy, sometimes described as dialysis dementia in long-term patients. Because of this accumulation risk, aluminum-containing antacids should be used with caution or avoided in individuals with reduced kidney function.

Calcium carbonate, while it can worsen calcium balance and contribute to vascular calcification in CKD, does not accumulate in the same way. Magnesium-containing antacids can lead to hypermagnesemia in CKD due to decreased excretion, and sodium bicarbonate raises sodium load and fluid retention, but the hallmark accumulation concern is particularly about aluminum compounds in kidney disease.