Long-term adefovir therapy may induce Fanconi syndrome: A report of four cases

Exp Ther Med. 2017 Jul;14(1):424-430. doi: 10.3892/etm.2017.4483. Epub 2017 May 22.

Abstract

Fanconi syndrome is a rare disease characterized by dysfunction of the proximal renal tubules as a result of various pathogenic events. Drug-induced Fanconi syndrome may be neglected or misdiagnosed, which increases the level of suffering. The aim of the present study was to conduct an investigation into the effects of adefovir (ADV)-induced Fanconi syndrome. Four typical cases of Fanconi syndrome caused by long-term ADV therapy (2-9 years) were diagnosed at our hospital. A complete medical and therapy history was collected from all four patients prior to a physical examination. Laboratory and diagnostic examinations were also conducted. Following this, the patients were diagnosed and a treatment regimen was decided upon. Outcomes of the treatment regimen were observed. Common manifestations of all the four patients were: Renal tubular reabsorption dysfunction; imbalanced electrolyte acid-base ratio; elevated cystatin C levels; severe hypophosphatemia and diffused systemic pain; osteoporosis; and difficultly walking. When ADV was replaced with supportive treatment, all the four patients exhibited symptom relief. These findings indicate that long-term ADV therapy may induce Fanconi syndrome. For patients with a history of such therapy, the possibility of Fanconi syndrome should be assessed and monitored closely for indicators, including altered glomerular and renal tubular function. Once diagnosed, the agent should be immediately discontinued and prompt symptomatic treatment should be administered.

Keywords: Fanconi syndrome; adefovir; antiviral therapy; chronic hepatitis B virus; electrolyte disturbances; kidney damage; osteoporosis.