Treatment of Hypomagnesemia

Serum magnesium concentration is determined by the interplay of intestinal absorption and renal excretion. Hypomagnesemia can occur as a result of insufficient magnesium intake, increased gastrointestinal or renal loss, or redistribution from extracellular to intracellular compartments. A number of drugs are known to cause hypomagnesemia, including proton pump inhibitors (PPIs). We report the case of a patient with symptomatic hypomagnesemia due to short bowel syndrome and PPI therapy. Investigations revealed low 24-hour urinary magnesium excretion and secondary hypocalcemia. PPI treatment was withdrawn and the patient was managed with intravenous and oral magnesium and calcium replacement. This teaching case provides an evidence-based discussion of the treatment of hypomagnesemia.