title: From hypomagnesaemia to Zollinger-Ellison syndrome: an adverse effect of a proton pump inhibitor.
abstract: We describe the case of a 53-year-old man who presented with abdominal pain, diarrhoea and hypomagnesaemia. The hypomagnesaemia proved to be due to gastrointestinal loss as urinary fractional excretion was very low, suggesting non-renal loss. Common causes were discarded and the hypomagnesaemia was attributed to chronic use of the proton pump inhibitor, omeprazole. As such, omeprazole was discontinued and an H2 blocker was given. Several days later the patient presented with upper gastrointestinal bleeding. CT scan demonstrated marked enlargement of the duodenum and proximal jejunum, and abnormal thickening and enhancement of the bowel wall. Urgent oesophagogastroduodenoscopy revealed coffee-ground and bloody contents in the distal oesophagus and stomach, and numerous ulcers along the duodenum and jejunum. A positron emission tomography-CT scan using GA 68-DOTANOC demonstrated increased uptake in the gastroduodenum junction, suggesting a neuroendocrine tumour. Pancreaticoduodenectomy was performed and tumour cells stained positive for gastrin, confirming the tentative diagnosis of Zollinger-Ellison syndrome.
authors.affiliation: Department of Internal Medicine H, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Allon
authors.initials: A
authors.lastname: Eyal
authors.affiliation: Gastroenterology Institute, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Alain
authors.initials: A
authors.lastname: Sueissa
authors.affiliation: Infectious Diseases Unit and Internal Medicine H, Rambam Health Care Campus and the Rappaport's Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Braun
authors.affiliation: The B. Shine Rheumatology Unit and Internal Medicine H, Rambam Health Care Campus and the Rappaport's Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Mohammad Ebrahim
authors.initials: ME
authors.lastname: Naffaa
mesh_terms: D004379:Duodenal Neoplasms / Q000150:complications*; D004381:Duodenal Ulcer / Q000209:etiology*; D015408:Gastrinoma / Q000150:complications*; D006801:Humans; D008274:Magnesium; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000009:adverse effects*; D010438:Peptic Ulcer Hemorrhage / Q000209:etiology*; D054328:Proton Pump Inhibitors / Q000009:adverse effects*; D014883:Water-Electrolyte Imbalance / Q000139:chemically induced*; D015043:Zollinger-Ellison Syndrome / Q000150:complications*
chemical_list: D054328:Proton Pump Inhibitors; D008274:Magnesium; D009853:Omeprazole