Table 4.

Tenofovir formulations

	TAF	TDF
Mechanism of action	Prodrug of tenofovir that undergoes intracellular metabolism by cathepsin A	Undergoes an initial diester hydrolysis to convert to tenofovir and subsequent phosphorylations by cellular enzymes to form tenofovir diphosphate
Indication	HIV, HBVa	HIV, HBV, PrEP
Plasma concentration	80–90% reduction in plasma levels	High
Intracellular concentration	5.3-fold higher compared to TDF	Low
Dosing	Formulated as a STR: 10 mg Formulated with emtricitabine: 25 mg	300 mg
Renal dosing considerations	CrCl >30 ml/min	CrCl >50 ml/min
Adverse event	Reduced renal and bone side effects	Higher rate of renal and bone side effects

CrCl creatinine clearance, HBV hepatitis B virus, PrEP pre-exposure prophylaxis, STR single tablet regimen, TAF tenofovir alafenamide, TDF tenofovir disoproxil fumarate

^aData were recently presented to support the use of TAF for HBV, but it is not currently approved for this indication