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.

Dolutegravir is an integrase inhibitor that is meant to be used as part of combination therapy for the treatment of HIV. Dolutegravir inhibits HIV integrase by binding to the integrase active site and blocking the strand transfer step of retroviral deoxyribonucleic acid (DNA) integration which is essential for the HIV replication cycle. Dolutegravir coadministered with dofetilide can result in potentially life-threatening adverse events.

Rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) which is used for the treatment of HIV-1 infections in treatment-naive patients. It is active against wild-type and NNRTI-resistant HIV-1. Rilpivirine is a diarylpyrimidinethat inhibits HIV-1 replication by non-competitive inhibition of HIV-1 reverse transcriptase (RT). Rilpivirine does not inhibit the human cellular DNA polymerases α, β and γ.

Raltegravir (RAL, Isentress, formerly MK-0518) is an antiretroviral drug produced by Merck & Co., used to treat HIV and it is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in patients 4 weeks of age and older. Raltegravir inhibits the catalytic activity of HIV-1 integrase, an HIV-1 encoded enzyme that is required r viral replication. Inhibition of integrase prevents the covalent insertion, or integration, of unintegrated linear HIV-1 DNA into the host cell genome preventing the formation of the HIV-1 provirus. The provirus is required to direct the production of progeny virus, so inhibiting integration prevents propagation of the viral infection. Raltegravir did not significantly inhibit human phosphoryl transferases including DNA polymerases α, β, and γ. Coadministration with others drugs that are strong inducers of UGT1A1, such as rifampin, may result in reduced plasma concentrations of raltegravir. The most common adverse reactions of moderate to severe intensity (≥2%) are insomnia, headache, dizziness, nausea and fatigue. Severe, potentially life-threatening, and fatal skin reactions have been reported. This include cases of Stevens-Johnson syndrome and toxic epidermal necrolysis. Hypersensitivity reactions have also been reported and were characterized by rash, constitutional findings, and sometimes, organ dysfunction, including hepatic failure. The major mechanism of clearance of raltegravir in humans is UGT1A1-mediated glucuronidation.

Darunavir (trade name Prezista) is an orally active bis-furan-sulfonamide inhibitor of human immunodeficiency virus (HIV-1) protease. Darunavir was developed by Tibotec Pharmaceuticals (now Janssen R&D Ireland). Darunavir is indicated for the treatment of HIV-1 infection in adult and pediatric patients 3 years of age and older. The drug is co-administered with low-dose ritonavir and other anti-HIV agents. It is the only antiretroviral that has been registered at two different doses, 800/100 mg once-daily or 600/100 mg twice-daily, allowing its administration throughout the entire course of HIV disease, from naive subjects without any HIV-1 resistance to heavily treatment-experienced subjects with widespread triple-class family resistance.