Reverse transcriptase inhibitors (RTIs) are a class of
antiretroviral drug used to treat HIV , and cancer . RTIs
inhibit activity of reverse transcriptase , a viral DNA
polymerase enzyme that HIV needs to reproduce. When HIV infects
a cell, reverse transcriptase copies the viral single stranded
RNA genome into a double-stranded viral DNA . The viral DNA is
then integrated into the host chromosomal DNA, which then allows
host cellular processes, such as transcription and translation
to reproduce the virus. RTIs block reverse transcriptase's
enzymatic function and prevent completion of synthesis of the
double-stranded viral DNA, thus preventing HIV from multiplying.
RTIs come in three forms: The mode of action of NRTIs and NtRTIs
is essentially the same; they are analogues of the naturally
occurring deoxynucleotides needed to synthesize the viral DNA
and they compete with the natural deoxynucleotides for
incorporation into the growing viral DNA chain. However, unlike
the natural deoxynucleotides substrates, NRT