Tenofovir at the Crossroad of the Therapy and Prophylaxis of HIV and HBV Infections

Tenofovir, alias (R)-PMPA, was first divulged as an antiHIV agent in 1993 [1]. That it would in 2012, become the first antiretroviral agent, approved by the US FDA (Food and Drug Administration) to prevent HIV infection, could have been predicted from the findings of Tsai et al. [2] showing the complete prevention of SIV (simian immunodeficiency virus) infection by (R)-PMPA in rhesus macaques. The limited oral bioavailability of (R)PMPA prompted the design of an orally available prodrug, the bis (isopropyloxycarbonylmethyl) or disoproxil derivative [3,4], which would later be formulated as the fumarate salt, TDF (tenofovir disoproxil fumarate).