Tetany Secondary to the Use of a Proton-Pump Inhibitor

Abstract

Introduction: Chronic PPI use has been reported to cause hypocalcemia, bone density loss and osteoporoticrelated fractures but an acute drop in serum calcium level with PPI use is rare. We present a rare case of symptomatic hypocalcemia with 2 weeks use of PPI. Case Report: 61-year-old female with past medical history of hypothyroidism and hypoparathyroidism secondary to thyroidectomy and parathyroidectomy came to the emergency department(ED) with complaints of spasm and twitching of her upper extremities associated with lethargy and difficulty ambulation. 2 weeks prior to this presentation patient had upper endoscopy done for dyspepsia which showed antral erythema and stomach biopsies came back positive for Helicobacter Pylori gastritis. Patient started taking omeprazole after the endoscopy and later she was given antibiotics treatment for Helicobacter Pylori which she started taking three days prior to the ED presentation. Prior to initiate the omeprazole patient's serum calcium was 8.1 mg/DL. The patient has been taking magnesium citrate 200 mg two times a day and calcium carbonate 1200 mg daily with meals since surgery. No recent change in the dosage of these medications. In ED, EKG done showed QT prolongation, serum calcium was 5.7 mg/DL, magnesium was 1.7 mg/DL and albumin was 3.3 g/DL Thyroid function was within normal limit and parathyroid hormone(PTH) was Discussion Gastric acidic PH is required for absorption of the calcium. Calcium carbonate is a widely use form of calcium supplement which become soluble in the gastric acidic PH and then get absorb in the small intestine. PPI increase the gastric PH so decrease the absorption of calcium which later can cause hypocalcemia. This effect is more seen in the patient with low PTH as it plays a key role in maintaining the serum calcium level within normal limit by stimulating bone resorption, renal tubular calcium reabsorption, and by enhancing gastrointestinal absorption of calcium. The patients with hypoparathyroidism when take PPI their serum calcium needs to be closely monitored to avoid the life threatening complication of hypocalcemia and should be advised to take calcium citrate as a calcium supplement which does not require gastric acidic PH.