An Uncommon Cause of Pathological Fracture: Tenofovir-induced Osteomalacia and acquired Fanconi's Syndrome in a Retroviral Patient

Abstract

ABSTRACT Here we report a 60-year-old female patient with retroviral illness on antiretroviral therapy with tenofovir/emitricitabine/ efavirenz since 4 years, who presented with fracture of the right 4th metatarsal and bone pains and was found to have hypophosphatemia with normal vitamin D, calcium, and parathormone levels. Further testing revealed elevated serum creatinine, phosphaturia, uricosuria, glycosuria, and metabolic acidosis supporting the diagnosis of Fanconi syndrome. Adverse drug reaction was suspected as the patient was on tenofovirbased regimen. Hence, it was stopped and, subsequently, oral phosphate supplementation was given. Patient improved after discontinuation of drug, confirming tenofovir as a cause of Fanconi syndrome. Serum phosphorous level returned to normal after 3 months of discontinuation of tenofovir. On follow-up, patient's phosphorous level was 3.2 mg/dL and oral phosphorous supplementation was stopped. This case shows the need for screening of proximal tubular function (serum creatinine, vitamin D levels, urine-phosphate, protein, and sugars). Usually tenofovir toxicity is reversible upon discontinuation of drug, but if toxicity goes unrecognized, prolonged usage of drug can cause irreversible tubular damage. How to cite this article Komandla SR, Monigari NK, Danturulu MV, Vidyasagar S. An Uncommon Cause of Pathological Fracture: Tenofovir-induced Osteomalacia and acquired Fanconi's Syndrome in a Retroviral Patient. J Postgrad Med Edu Res 2016;50(3):156-158.