Milk-alkali syndrome with a serum calcium level of 22 mg/dl and J waves on the ECG.

A man with severe hypercalcemia (22 mg/dl) secondary to ingestion of a calcium carbonate antacid (Tums) was admitted with obtundation and hyperreflexia, which disappeared with treatment. Laboratory values, which were consistent with milk-alkali syndrome, included low-normal serum chloride (96 mEq/L), normal phosphorus of 2.7 mg/dl (phosphorus is usually normal to increased in this syndrome), increased blood urea nitrogen (39 mg/dl), and increased serum creatinine (2.4 mg/dl). A normal C-terminal parathormone level helped distinguish this patient from patients with severe hypercalcemia due to primary hyperthyroidism. The ECG revealed a widened rather than a shortened QT interval, as well as a J wave, a broadened T wave, and a U wave with this marked hypercalcemia, all of which reverted to normal with correction of the hypercalcemia.