Tenofovir diphosphate is a weak inhibitor of mammalian DNA polymerases (alpha), (beta), and mitochondrial DNA polymerase (gamma).
Emtricitabine and tenofovir disoproxil fumarate: In combination studies evaluating the in vitro antiviral activity of emtricitabine and tenofovir together, synergistic antiviral effects were observed.
EMTRIVA is the brand name for emtricitabine, a synthetic nucleoside analog of cytidine.
Tenofovir disoproxil fumarate (VIREAD, also known as tenofovir DF) is converted in vivo to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5'-monophosphate.
In drug combination studies of emtricitabine with nucleoside reverse transcriptase inhibitors (abacavir, lamivudine, stavudine, zalcitabine, zidovudine), non-nucleoside reverse transcriptase inhibitors (delavirdine, efavirenz, nevirapine), and protease inhibitors (amprenavir, nelfinavir, ritonavir, saquinavir), additive to synergistic effects were observed.
Most of these drug combinations have not been studied in humans.
The partition coefficient (log p) for tenofovir disoproxil is 1.25 and the p Ka is 3.75.