Bisphosphonates are commonly used to treat osteoporosis. While renal toxicity is common with pamidronate and zoledronate, few ibandronate-related cases are reported. We describe a rare case of ibandronate-associated nephrotoxicity. An 88-year-old woman was admitted for edema. She had been receiving intravenous ibandronate treatment for postmenopausal osteoporosis and had no other diagnosed diseases. She was presented with proteinuria, hypoalbuminemia (1.9 g/dL), and an elevated serum creatinine level (1.8 mg/dL). Renal biopsy revealed podocyte disease, favoring a diagnosis of focal segmental glomerulosclerosis. She was treated with diuretics, tacrolimus, and fimasartan. Steroids were avoided due to severe osteoporosis. Three months later, the edema had subsided and the laboratory findings had improved (serum albumin 3.5 g/dL, serum creatinine 0.97 mg/dL). This case emphasizes the importance of careful monitoring of proteinuria and renal function during ibandronate treatment. In older adult patients, kidney biopsy and immunosuppressive treatment may be considered based on physical activity and underlying diseases.
Keywords: Ibandronic acid; Nephrotic syndrome; Postmenopausal osteoporosis.