Indinavir is an antiretroviral drug for the treatment of HIV infection. Indinavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Indinavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs.

Saquinavir (brand names Invirase and Fortovase) is an antiretroviral drug used together with other medications to treat or prevent HIV/AIDS. Saquinavir is an inhibitor of HIV protease. HIV protease is an enzyme required for the proteolytic cleavage of viral polyprotein precursors into individual functional proteins found in infectious HIV. Saquinavir is a peptide-like substrate analog that binds to the protease active site and inhibits the activity of the enzyme. Saquinavir inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature noninfectious virus particles. The most frequent adverse events with saquinavir in either formulation are mild gastrointestinal symptoms, including diarrhea, nausea, loose stools & abdominal discomfort. Invirase is better tolerated than Fortovase.

Stavudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Stavudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA. Stavudine is used for the treatment of human immunovirus (HIV) infections. Stavudine is sold under the brand name Zerit among others.

Didanosine was developed by Bristol-Myers Squibb in collaboration with the NIH for the treatment of HIV-1 infections. Upon administration the drug is metabolized to the active metabolite which inhibits HIV-1 reverse transcriptase both by competing with deoxyadenosine 5'-triphosphate and by its incorporation into viral DNA. Didanosine was approved by FDA under the name Videx (among the other names).

Atevirdine (U-87201E) is a nonnucleoside inhibitor of HIV-1 reverse transcriptase, that has been studied for the treatment of HIV infection. Atevirdine mesylate is the first-generation member of the bisheteroarylpiperazine class of nonnucleoside inhibitors, which inhibits reverse transcriptase noncompetitively by binding near the catalytic site. The safety, tolerability, and antiviral activity of atevirdine were studied in phase I/II clinical trial. Rash was the most common adverse event, with a grade 3 or 4 rash. No significant change from baseline in HIV-1 plasma RNA mean copy number was detected.

Dapivirine, an anti-retroviral (ARV)-based microbicide, is a substituted diaminopyrimidine (DAPY) derivative and a potent non-nucleoside reverse-transcriptase inhibitor (NNRTI) with antiviral activity against HIV-1. Dapivirine showed high activity against wild-type and mutant HIV in in virto HIV models inhibiting a broad panel of HIV-1 isolates from different classes, including a wide range of NNRTI-resistant isolates. Developed by Janssen Sciences (formerly Tibotec Pharmaceuticals), dapivirine was initially tested as an oral treatment for HIV in a number of Phase I/II clinical trials. In 2014 the International Partnership for Microbicides (IPM) began its work on the monthly dapivirine ring. Phase I/II clinical trials in Africa, Europe and the United States proved that dapivirine is safe and well-tolerated. Phase III long-term safety and efficacy studies of the monthly dapivirine ring as part of IPM's Dapivirine Ring Licensure Program confirmed that the monthly dapivirine ring can safely help prevent HIV infection in women. In 2016 the ASPIRE Study reported a 27 percent reduction in HIV-1 acquisition with a trend toward greater protection in women over age 21 and no significant protection for women under age 21.

Tifuvirtide (also known as T 1249) is a synthetically designed hybrid retroviral envelope polypeptide patented by Trimeris, Inc. as fusion inhibitor useful for the treatment of HIV infection. Tifuvirtide binds to HIV glycoprotein 41 (gp41) and prevents its fusogenic conformation, inhibiting viral entry into host cells. Tifuvirtide is composed of sequences from HIV-1, HIV-2, and simian immunodeficiency virus. Tifuvirtide has greater potency in vitro, compared with enfuvirtide, and elicits activity against most enfuvirtide-resistant isolates in vitro and in vivo. A successful short-term phase 1/2 studies evaluation of antiretroviral activity and safety in humans proved the potential of this new drug, although further clinical development was discontinued.

Enfuvirtide is a linear 36-amino acid synthetic peptide that inhibits the fusion of HIV-1 with CD4 cells. Enfuvirtide works by disrupting the HIV-1 molecular machinery at the final stage of fusion with the target cell, preventing uninfected cells from becoming infected. Enfuvirtide interferes with the entry of HIV-1 into cells by inhibiting fusion of viral and cellular membranes. Enfuvirtide binds to the first heptad-repeat (HR1) in the gp41 subunit of the viral envelope glycoprotein and prevents the conformational changes required for the fusion of viral and cellular membranes. Enfuvirtide is indicated for the treatment of HIV-1 infection, in combination therapy with other antiretrovirals, in patients where all other treatments have failed. Common adverse drug reactions associated with enfuvirtide therapy include: injection site reactions (pain, hardening of skin, erythema, nodules, cysts, itch; experienced by nearly all patients, particularly in the first week), peripheral neuropathy, insomnia, depression, cough, dyspnoea, anorexia, arthralgia, infections (including bacterial pneumonia) and/or eosinophilia.

Bictegravir is a component of the fixed-dose combination product bictegravir/emtricitabine/tenofovir alafenamide (BIKTARVY®), which received marketing approval for the treatment of human immunodeficiency virus (HIV) infection by the U.S. Food and Drug Administration in February 2018. Bictegravir inhibits the strand transfer activity of HIV-1 integrase, an HIV-1 encoded enzyme that is required for viral replication. Inhibition of integrase prevents the integration of linear HIV-1 DNA into host genomic DNA, blocking the formation of the HIV-1 provirus and propagation of the virus.