Antacid overuse linked to kidney failure, study warns

Sarah Slater

The chronic overuse of over-the-counter antacids can cause renal failure, data shows.

The dangers have been revealed in the case of a 42-year-old man who presented with a four-week history of nausea, vomiting, and abdominal pain, ultimately found to be caused by chronic overuse of calcium carbonate tablets for gastro-oesophageal reflux disease (GORD).

Co-authors of the University Hospital Limerick (UHL) study Antacid Abuse: A Case of Milk-Alkali Syndrome in the monthly edition of the Irish Medical Journal, highlight that the case “emphasises” the need for awareness among healthcare professionals regarding the syndrome as a potential consequence of over-the-counter antacid use and “underscores the importance of careful medication history review and patient education to prevent complications”.

The man presented to the hospital with a four-week history of nausea, vomiting, constipation, and mild abdominal pain. His history included chronic dyspepsia, significant alcohol use, and smoking.

The patient reported consuming 10 to 12 calcium carbonate (Rennie®) tablets daily for two years to manage reflux symptoms.

He denied using diuretics or vitamin D supplements.

Risk factors due to chronic use include reduced renal calcium excretion, with patients with chronic kidney disease (CKD) or impaired kidney function being particularly vulnerable.

Laboratory results showed a severe rise in his sugar levels, serious effects on the pH level of the blood, and acute kidney injury.

He was treated with intravenous normal saline, and a single 4mg dose of zoledronic acid was administered. Serum calcium normalised within six days, and creatinine levels and kidney function improved.

The co-authors added that the patient’s rapid recovery following treatment “underscores the reversibility” of the syndrome when diagnosed early.

“Given the widespread use of calcium supplements, public education on safe calcium intake and potential drug interactions is essential. Clinicians should remain vigilant for the syndrome in patients, as early recognition prevents long-term renal complications.