Fanconi syndrome related to zoledronic acid

• Autor(a) principal: Oliveira,Margarida
• Data de Publicação: 2019
• Outros Autores: Santos,M. Teresa, Costa,Ana
• Tipo de documento: Relatório
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692019000300008
• topic: Fanconi Syndrome; Nephrotoxicity; Renal tubular acidosis; Zoledronic Acid

Abstract: Fanconi syndrome is characterized by proximal tubular dysfunction, with inability to reabsorb bicarbonate causing type 2 renal tubular acidosis associated with aminoaciduria, normoglycemic glycosuria, hypophosphatemia with phosphaturia and proteinuria. A 68-year-old man with a history of type 2 diabetes mellitus, high-grade papillary carcinoma of the bladder, submitted to transurethral resection in 2011 and 2013 had prostatic adenocarcinoma diagnosed in 2015 with bone metastasis under zoledronic acid. The patient was referred to the emergency department because of anemia “de novo” and acute on chronic kidney injury. Urinary sediment showed nonnephrotic proteinuria and renal ultrasound was normal. He had hyperchloremic metabolic acidosis with hypokalemia, hypophosphatemia, hypocalcemia, hypouricemia, without glycosuria. No evidence of hemolysis nor abnormalities in serum and urinary immunoelectrophoresis, endoscopic studies, myelogram, or bone marrow biopsy. Renal biopsy was compatible with acute tubular necrosis superimposed on diabetic and hypertensive nephropathy. Zoledronic acid was suspended and we observed slow improvement of renal function and resolution of metabolic acidosis and ionic disorders. Zoledronic acid is nephrotoxic and may induce tubular dysfunction, which can cause Fanconi syndrome. Since 2012, there have been cases relating the administration of zoledronic acid for bone metastasis or hypercalcemia associated with malignant neoplasia with Fanconi syndrome. Although it is a rare association, it is a potentially fatal complication and renal function monitoring is essential.