A case of antacid-associated osteomalacia / 대한내과학회지

ABSTRACT

Chronic heavy use of phosphate-binding antacids has been known to cause osteomalacia. However, in spite of widespread use of antacids without prescription, there was no case report of osteomalacia associated with antacids in Korea. We report a case of osteomalacia diagnosed in a 36-year-old woman who had ingested large amounts of aluminum-containing antacids due to epigastric soreness. She had consumed about 4.2 kg of aluminum hydroxide over 10 years until she had withdrawn antacids 3 months before she was admitted with non-traumatic fractures of bilateral femur necks. Biochemical tests revealed normal levels of serum calcium and iPTH, increased level of serum alkaline phosphatase, and normal renal function. Bone mineral density (BMD) values of lumbar spines were decreased (T-score=-3.99~-3.11). Bone biopsy showed abundant unmineralized osteoid indicating osteomalacia. She was treated with bilateral total hip replacement arthroplasty and recommended not to restart the ingestion of antacids. After thirty months' withdrawal of antacids, BMD values of lumbar spines were found to be improved (T-score=-2.3~-1.4).