Antiretroviral drugs target retroviruses, especially HIV. These include nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), fusion inhibitors, entry inhibitors, HIV integrase strand transfer inhibitors, and multiclass combination products.

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

NRTIs interfere with the ability of reverse transcriptase, the enzyme that allows the synthesis of DNA from viral RNA, to make DNA by resembling the nucleosides normally incorporated into DNA. The nucleotide analogues prevent reverse transcriptase from attaching additional nucleotides to the viral DNA strand.

Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)

NNRTIs interfere with reverse transcriptase by binding to the enzyme, preventing its proper function.

Protease Inhibitors (PIs)

PIs prevent viral proteins from being properly folded into correct conformations by binding to the protease enzyme.

Fusion Inhibitors

Fusion inhibitors bind to a protein on the envelope of the virus, which interferes with the virus's ability to fuse with the cell membrane, hence preventing the virus from entering the cell.

Entry Inhibitors

Entry inhibitors act on the cell rather than the virus, to prevent viral infection of a cell. These inhibitors bind to coreceptors on the cell's surface to interrupt the process of viral entry into the cell.

Integrase Inhibitors

Integrase is an enzyme used by the retrovirus to integrate the viral DNA created by reverse transcriptase into the host cell's chromosome. Integrase inhibitors disrupt the function of the integrase enzyme.

Source:

NIH: Retrovirus Genomes

UCSF: About the Antiretroviral Drug Profiles

More Information:

FDA: Antiretroviral Drugs Used in the Treatment of HIV Infection