Fanconi Syndrome Due to Tenofovir Disoproxil Fumarate in a Patient with Chronic Hepatitis B Induced Cirrhosis: A Case Report

We present a 63-year-old woman with chronic hepatitis B. The patient has a history of cirrhosis due to chronic hepatitis B and is under treatment with Tenofovir disoproxil fumarate. The patient presented to our center with nausea, vomiting, and severe metabolic acidosis. After initial evaluation, along with the typical course of events and the exclusion of differential diagnoses of normal anion gap metabolic acidosis, we determined that the cause of illness was related to Tenofovir disoproxil fumarate. All our practical and laboratory data supported a diagnosis of proximal tubular acidosis. After discontinuing the drug for two weeks and providing supportive management, metabolic acidosis and electrolyte imbalance improved. The other isoform of Tenofovir (Tenofovir alafenamide) was initiated for the patient, and after two months of followup, there were no signs of acidosis or electrolyte imbalance.