NCIt definition : A fixed combination of abacavir sulfate, a nucleoside reverse transcriptase inhibitor
(NRTI) analog of guanosine and lamivudine, an NRTI analog of cytidine, that is used
to treat human immunodeficiency virus (HIV) infection. Upon oral administration, abacavir
and lamivudine are phosphorylated into active metabolites that compete for incorporation
into viral DNA. These metabolites inhibit the HIV reverse transcriptase (RT) enzyme
competitively and act as a chain terminator of DNA synthesis. This interferes with
the generation of DNA copies of viral RNA, which is necessary for the synthesis of
new virions.;