Severe hypomagnesemia during long-term treatment with a proton pump inhibitor

Severe hypomagnesemia is a serious clinical condition that can be complicated by life-threatening arrhythmias (ventricular tachycardia, ventricular fibrillation, and torsades de pointes) and neurologic manifestations (neuromuscular hyperexcitability, frank ataxia, confusion, delirium, and seizures). Moreover, hypokalemia and hypocalcemia frequently are documented as accompanying electrolyte disorders. [1] and [2] Hypomagnesemia is relatively common in hospitalized patients,3 particularly in intensive care units. [4], [5] and [6] Leading causes of the acquired disorder are malabsorption, uncontrolled diabetes, chemotherapy, acute pancreatitis, drugs, and refeeding. [2] and [7] Very few cases of severe hypomagnesemia related to long-term use of proton pump inhibitors (PPIs) have been published to date, [8], [9], [10], [11] and [12] and the likely pathogenetic mechanisms are not fully elucidated. We report a case of severe symptomatic hypomagnesemia in a patient treated with PPIs for many years because of Barrett esophagus. The differential diagnosis and potential pathogenetic mechanisms are discussed within a more general conceptual framework of the pathophysiology state of serum magnesium homeostasis.