Another case of milk–alkali syndrome or a learning opportunity?

[摘要] Milk–alkali syndrome (MAS) is a triad of hypercalcaemia, metabolic alkalosis and renal insufficiency. In this study, we present a case of milk–alkali syndrome secondary to concurrent use of over-the-counter (OTC) calcium carbonate-containing antacid tablets (Rennie®) for dyspepsia and calcium carbonate with vitamin D3 (Adcal D3) for osteoporosis. A 72-year-old woman presented with a 2-day history of nausea, vomiting, epigastric pain, constipation, lethargy and mild delirium. Past medical history included osteoporosis treated with daily Adcal D3. Initial blood tests showed elevated serum-adjusted calcium of 3.77 mmol/L (normal range, 2.2–2.6) and creatinine of 292 µmol/L (45–84) from a baseline of 84. This was corrected with i.v. pamidronate and i.v. fluids. She developed asymptomatic hypocalcaemia and rebound hyperparathyroidism. Myeloma screen, vasculitis screen and serum angiotensin-converting enzyme (ACE) were normal, while the CT of the chest, abdomen and pelvis showed renal stones but no malignancy. A bone marrow biopsy showed no evidence of malignancy. Once the delirium resolved, we established that prior to admission, she had been excessively self-medicating with over-the-counter antacids (Rennie®) as required for epigastric pain. The increasing use of calcium preparations for the management of osteoporosis in addition to easily available OTC dyspepsia preparations has made MAS the third most common cause of hypercalcaemia hospitalisations. Educating patients and healthcare professionals on the risks associated with these seemingly safe medications is required. Appropriate warning labels on both calcium preparations used in the management of osteoporosis and OTC calcium-containing preparations would prevent further similar cases and unnecessary morbidity and hospital admission.

[学科分类] 血液学