An approach to the diagnosis and management of a case presenting with recurrent hypomagnesemia secondary to the chronic use of a proton pump inhibitor.

PURPOSE: Magnesium is an important electrolyte for very many cell functions and its deficiency may lead to a wide spectrum of diseases. We report a clinical case of hypomagnesemia resulting from the chronic use of a proton pump inhibitor (PPI). PPIs are drugs widely used in medical practice, and a growing number of cases of PPIs causing hypomagnesemia have been described. Our aim was to monitor the clinical and electrolyte findings during recovery from hypomagnesemia caused by long-term PPI use.

RESULTS

A 65-year old female who had been using omeprazole for 10 years, presented with arrhythmia and paresthesia of the lower and upper limbs that had been attributed to severe hypomagnesemia, hypocalcemia, and hypoparathyroidism. Her laboratory tests revealed the following results: magnesium 0.6 mg/dL (NR: 1.5 to 2.5 mg/dL), calcium 7.3 mg/dL (NR: 8.5 to 10.2 mg/dL), parathyroid hormone (PTH) 13.3 pg/mL (NR: 15 to 65 pg/mL), and low urinary calcium and magnesium excretion. Her electrocardiogram disclosed typical, prolonged QT interval, ST depression, and U waves. We discuss the differential diagnoses, pathophysiology, and reversibility of symptoms after effective treatment of the hypomagnesemia.

CONCLUSION

this report emphasizes that even if long-term PPI users appear largely asymptomatic, life-threatening arrhythmias can present very suddenly. Long-term PPI users should be monitored for otherwise unexplained hypomagnesemia, hypocalcemia, functional hypoparathyroidism and associated symptoms.