ACTA ENDOCRINOLOGICA (BUC)

Context. This is the first case of proton pump induced hypomagnesemia and hypocalcemia, accompanied with increased parathormone levels. Objective. The proton pump inhibitors are widely used medications. They are considered safe, however, they have some side effects. One of these side effects is hypomagnesemia. Here we report a case with severe hypocalcemia and hypomagnesemia due to long term proton pump inhibitor. Case. A 73 years old woman, admitted to emergency room due to generalized tonic-clonic seizures. She had a previous history of muscle cramps and paresthesia for 4 months. She had a medical history of peptic ulcer and she was taking omeprazole for 7 years. Her laboratory evaluation showed marked hypomagnesemia [0.5 mg/dL (normal: 1.7-2.55 mg/dL)] and hypocalcemia [6.2 mg/dL (8.8-10.2 mg/ dL)] with extremely low urinary calcium (Ca) and magnesium (Mg) excretion [0.01 gr/24 h (normal:0.05-0.3 gr/24 h), <1.22 mg/24 h (normal: 9.7-12.20) respectively]. Her vitamin D level was normal [35 ng/ mL (normal:30-80 ng/mL)] and PTH was increased [129 pg/mL (normal: 15-65 pg/ mL)] in accordance with the secondary hyperparathyroidism. Symptoms resolved with the intravenous supplementation of calcium gluconate and magnesium sulphate. However, despite high levels of oral replacement, Mg levels remained low. With omission of omeprazole two months after the admission, her ion levels returned to normal without any replacement. Conclusion. Especially elderly patients with long term proton pump inhibitor therapy, should be monitored for the symptoms of hypocalcemia and hypomagnesemia.