Osteopenia in a young man associated with the use of tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate is a recommended first‐line therapy for patients with chronic hepatitis B, although the frequent Tenofovir disoproxil fumarate related adverse drug reactions are nephrotoxicity and bone toxicity. We described the case of a 21‐year‐old Han Chinese male patient with chronic hepatitis B with tenofovir disoproxil fumarate‐associated osteopenia. The patient presented osteopenia at the site of his femoral neck with bone mineral density 0.865g/cm(2) (Z = −1.9) in January 2020. Nine months after switching to TAF, bone mineral density at left femoral neck improved to 0.978g/cm(2) (Z = −1.0) in September 2020. Bone mineral density of this patients was normal in January 2021. This is the first report in very young man presenting tenofovir disoproxil fumarate‐associated osteopenia.