HIV Treatment Regimens

Though there is no cure for HIV at this time, there are medications used to treat and suppress the virus. Eventually, a person’s viral load can become "undetectable." This means that the amount of HIV in the blood is so low that the virus is not detected when tested. Controlling viral load is essential for those with HIV to lead a longer life with fewer HIV-related complications.1-3

Research suggests that people who achieve and maintain an undetectable viral load have virtually no risk of transmitting the virus to an HIV-negative partner. This idea has been referred to as "undetectable = untransmittable" or "U=U." Therefore, the risk of HIV transmission to an HIV-negative partner can be reduced when an HIV-positive partner is on ART and taking their medications as prescribed.1-3^1-3

HIV treatment regimens

Treatment with multiple HIV medications from a variety of different drug classes is the most effective way for people with HIV to achieve an undetectable viral load. Using multiple medicines or types of medicines to treat HIV is referred to as antiretroviral therapy (ART) or combination antiretroviral therapy (cART).1,4,5

In the past, HIV treatment options were available only as medicines that contained 1 active ingredient (monotherapy). Today, combination therapies that combine multiple drugs, usually from different drug classes, are available in 1 tablet. This helps make taking and sticking to to HIV treatment simpler. This is especially important in preventing HIV from mutating and developing resistance against a medication.1,4,5

HIV drug classes

HIV medications can be separated into different categories, called drug classes. Each drug class targets a different point in the HIV life cycle. The main HIV drug classes in order of the life cycle steps they impact include:^4,5

• CCR5 antagonists
• Post-attachment inhibitors
• Fusion inhibitors
• Nucleoside reverse transcriptase inhibitors (NRTIs)
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
• Integrase inhibitors
• Protease inhibitors
• Pharmacokinetic enhancers

Targets of different HIV drug classes

The first two steps of the life cycle are called binding and fusion and focus on HIV getting into a human CD4 cell, or T cell. Once inside, the virus needs to disassemble itself and begin the replication process. The drug classes that interfere with the binding and fusion process include CCR5 antagonists, post-attachment inhibitors, and fusion inhibitors.6

The next three steps represent the replication process of the virus’s genetic material. These processes are called reverse transcription, integration, and replication. The drug classes that act here include NRTIs, NNRTIs, and integrase inhibitors.6

The last two steps of the process involve HIV re-assembling itself into new, mature virions that can be released from the CD4 cell and enter the bloodstream where they can go on to infect new cells. Protease inhibitors act at this step and prevent the assembly process.6

Fully formed HIV carries around with it its viral RNA (its genetic material) and several enzymes, including the reverse transcriptase enzyme, the integrase enzyme (both involved in replication), and the protease enzyme. An HIV virion is not considered complete and able to infect more CD4 cells without all of these components.6

A pharmacokinetic enhancer does not treat HIV directly but rather enhances the effect of certain HIV-fighting drugs, such as protease inhibitors or integrase inhibitors, that are used alongside it.6

Combination therapies

Many combination therapies are designed to be standalone therapies and should not be taken with other HIV medicines. Others need to be taken with other HIV medicines. Your doctor will help you determine which treatment plan is right for you.4,5

Examples of combination therapies include:4,5

• Atripla^® (efavirenz, emtricitabine, and tenofovir disoproxil fumarate)
• Bitktarvy^® (bictegravir, emtricitabine, and tenofovir alafenamide)
• Combivir (lamivudine and zidovudine)
• Complera^® (emtricitabine, rilpivirine, and tenofovir disoproxil fumarate)
• Dovato (dolutegravir and lamivudine)
• Epzicom (abacavir and lamivudine)
• Genvoya^® (elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide)
• Kaletra^® (lopinavir and ritonavir)
• Symfi^®/Symfi Lo^® (efavirenz, lamivudine, and tenofovir disoproxil fumarate)
• Truvada^® (emtricitabine and tenofovir disoproxil fumarate)