Calcium Carbonate (Tums)-Associated Hypercalcemic Crisis.

Hypercalcemic crisis due to severe decompensated hypercalcemia represents a life-threatening medical emergency leading to renal failure and altered mental status. Hypercalcemic crisis most commonly results from hypercalcemia of malignancy, undiagnosed primary hyperparathyroidism, granulomatous diseases, and medication-induced hypercalcemia. Commonly prescribed medications like thiazide diuretics, lithium therapy, and teriparatide are among the medications known to cause hypercalcemia. Here, we describe a case of the hypercalcemic crisis caused by excessive calcium carbonate ingestion emphasizing physicians to be aware of this potentially life-threatening adverse effect of a widely available over-the-counter acid reflux medication and educate patients regarding the same.