[The milk-alkali syndrome--a rare differential diagnosis for hypercalcemia]

A 54-year-old man was hospitalised because hypercalcaemia and associated renal failure were suspected. He had a history suggesting gastric ulcer, with nonspecific back and shoulder pain and spontaneously passed kidney stone. On admission the patient reported reduction in physical fitness, fatigue, headache and nausea without vomiting. Physical examination was unremarkable except for pain on pressure over the thoracic and lumbar vertebrae.

Hypercalcaemia of 3.9 mmol/l was found while parathormone was low. Serum creatinine concentration was 2.8 mg/dl. Malignancy was excluded after extensive tests. A florid gastric ulcer was demonstrated, together with Helicobacter pylori infection. Computed tomography revealed stippled calcifications in the kidneys.

Renal function markedly improved, the hypercalcaemia disappeared and the parathormone level rose within four days of the administration of sodium chloride (2.51 daily of a 0.9% solution) and of furosemide (40 mg daily). Repeat questioning of the patient revealed that because of stomach pains he had for four years been taking up to 6 g calcium carbonate daily in the form of a prescription-free antacid. He was thereupon treated for a milk-alkali syndrome. Calcium concentration became normal, while renal function has remained slightly impaired a year later. The ulcer has healed without recurrence on eradication of the Helicobacter pylori infection with amoxicillin and omeprazole.

The danger of some "over the counter" prescription-free medications should not be underestimated and patients should be routinely questioned about them. Absorbable antacids should no longer be taken in the treatment of peptic complaints now that effective antacids, H2-receptor antagonists and proton-pump inhibitors have become available.