Tenofovir diphosphate is an inhibitor of HIV reverse transcriptase (Kis = 0.022 and 1.55 ?M for RNA and DNA, respectively) and hepatitis B virus (HBV) polymerase (Ki = 0.18 ?M).1,2 It is selective for these enzymes over DNA polymerase α and β, as well as mitochondrial DNA polymerase γ (Kis = 5.2, 81.7, and 59.5 ?M, respectively). Tenofovir diphosphate is formed intracellularly through phosphorylation of the prodrugs tenofovir and tenofovir disoproxil by nucleotide kinases.3 Increased levels of tenofovir diphosphate in isolated peripheral blood mononuclear cells (PBMCs) correlate with a decrease in the risk of simian HIV (SHIV) acquisition in a macaque model of rectal SHIV transmission.4
1.Cherrington, J.M., Allen, S.J.W., Bischofberger, N., et al.Kinetic interaction of the diphosphates of 9-(2-phosphonylmethoxyethyl)adenine and other anti-HIV active purine congeners with HIV reverse transcriptase and human DNA polymerases α, β and γAntivir. Chem. Chemother.6(4)217-221(1995) 2.Delaney, W.E., IV, Ray, A.S., Yang, H., et al.Intracellular metabolism and in vitro activity of tenofovir against hepatitis B virusAntimicrob. Agents Chemother.50(7)2471-2477(2006) 3.Robbins, B.L., Srinivas, R.V., Kim, C., et al.Anti-human immunodeficiency virus activity and cellular metabolism of a potential prodrug of the acyclic nucleoside phosphonate 9-R-(2-phosphonomethoxypropyl)adenine (PMPA), bis(isopropyloxymethylcarbonyl)PMPAAntimicrob. Agents Chemother.42(3)612-617(1998) 4.Anderson, P.L., Glidden, D.V., Bushman, L.R., et al.Tenofovir diphosphate concentrations and prophylactic effect in a macaque model of rectal simian HIV transmissionJ. Antimicrob. Chemother.69(9)2470-2476(2014)