Lactic acidosis & severe hepatomegaly w/ steatosis. Patient should be tested for presence of chronic hepatitis B virus (HBV) before initiating therapy. Severe acute exacerbations of hepatitis B in patients coinfected w/ HBV & HIV-1 after discontinuation of treatment. New onset or worsening renal impairment including acute renal failure & Fanconi syndrome. Do not co-administer w/ other drugs containing emtricitabine, tenofovir disoproxil fumarate, tenofovir alafenamide, lamivudine or adefovir dipivoxil. Decreased bone mineral density. Redistribution or accumulation of body fat including central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial wasting, breast enlargement & "cushingoid appearance". Immune reconstitution syndrome observed in HIV-infected patients may necessitate further evaluation & treatment. Carefully monitor & consider treatment modification in patients utilizing a triple nucleoside-only regimen. Use for PrEP only as part of a comprehensive prevention strategy including other prevention measures eg, safer sex practices. End-stage renal disease. Pregnancy & lactation. Childn <17 kg. Elderly ≥65 yr.