Antivirals Quiz

See HIV Antiretroviral Therapy. Option B is correct. HIV is a retrovirus: it carries its genes as RNA and uses its own enzyme, reverse transcriptase, to copy the RNA into DNA. The viral enzyme integrase then inserts this DNA into the host cell's own DNA. This integration step makes the infection permanent, because the viral genes are then copied along with the cell's own. Integrase strand transfer inhibitors (INSTIs) such as dolutegravir, raltegravir and bictegravir block integrase and stop this insertion. They are increasingly used as first-line treatment because of high efficacy and good tolerability, usually with two nucleoside reverse transcriptase inhibitors. A useful way to learn the classes is to follow the life cycle in order, with one class for each stage:

• Entry inhibitors (such as maraviroc) block attachment and entry into the cell
• NRTIs and NNRTIs block reverse transcriptase, which copies RNA into DNA
• Integrase inhibitors (dolutegravir, raltegravir, bictegravir) block insertion into the host genome
• Protease inhibitors (such as darunavir) block the maturation of viral proteins

• Integrase: The viral enzyme that inserts viral DNA into the host cell's DNA, which makes the infection permanent.
• INSTIs: Dolutegravir, raltegravir and bictegravir block integrase and stop this insertion.
• First-line use: Chosen for high efficacy and good tolerability, usually with two nucleoside reverse transcriptase inhibitors.