NCIt definition : A fixed combination of efavirenz, a non-nucleoside reverse transcriptase (RT) inhibitor
(NNRTI); emtricitabine, a nucleoside RT inhibitor (NRTI) analog of cytidine; and tenofovir
disoproxil fumarate, an NRTI analog of adenosine monophosphate, that is used to treat
human immunodeficiency virus (HIV) infection. Upon oral administration, efavirenz,
emtricitabine, and tenofovir disoproxil fumarate inhibit the activity of HIV RT by
competing with natural deoxyribonucleosides for incorporation into the growing viral
DNA chain resulting in early chain termination. This interferes with the generation
of DNA copies of viral RNA, which is necessary for the synthesis of new virions.;