How does antiretroviral therapy treat HIV?

The prognosis for people infected with HIV is much better than it was in previous decades. Improvements in prognosis have been driven by a better understanding of the virus, better screening methods, earlier treatment, and more effective medications.

Commonly referred to as HIV, human immunodeficiency virus is a chronic viral infection that attacks and damages the body’s immune system.

Untreated, HIV can progress to acquired immune deficiency syndrome (AIDS). If a person develops AIDS, the body will have little immunological defense against serious infections and certain types of cancer.

While there is no cure for HIV, the disease can be managed with treatment—and if you’ve been diagnosed with HIV, it is important to start treatment as soon as possible. Delaying treatment allows the virus to continue to multiply and cause damage to the immune system. This will increase the chances of the infection progressing to AIDS and/or other serious complications.

Antiretroviral therapy

The treatment for HIV infection is called antiretroviral therapy, often abbreviated as ART. These medications work by disrupting the lifecycle of HIV, preventing the virus from reproducing and enabling the immune system to remain strong.

The goal of ART treatment is to achieve and maintain viral suppression. This means that the amount of virus in the body is so little that it cannot be detected with standard blood tests. A person who is maintaining viral suppression can live a normal life and will not be able to transmit HIV to others.

However, viral suppression does not mean that an infection is cured or gone—the virus can multiply quickly if treatment is stopped, medications are skipped or taken inconsistently, or an infection becomes resistant to a medication.

Medication classes

There are dozens of different ART medications available. ART medications are categorized into different classes based on how the drugs interfere with the lifecycle of the HIV virus.

For example, the initial treatment of HIV often includes medications called NRTIs (nucleoside/nucleotide reverse transcriptase inhibitors). NRTIs work by blocking enzymes called reverse transcriptase, which HIV needs in order to make copies of itself. By blocking this enzyme, NRTIs disrupt the life cycle of the virus and prevent it from reproducing.

Classes of ART medications

• Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
• Protease inhibitors (PIs)
• Entry Inhibitors
• Fusion inhibitors (FIs)
• Integrase strand transfer inhibitors (ISTIs)
• Attachment inhibitors
• Post-attachment inhibitors
• Capsid inhibitors

Treatment regimens

People being treated for HIV are typically given a combination of several medications from different classes. This is the most effective way to reduce the amount of HIV in the body and maintain an undetectable viral load. A combination of ART drugs is called a treatment regimen.

Many ART regimens are taken as oral medications, which are taken every single day. Some medications combine two or more ART drugs into a single pill.

There are also long-acting ART medications that are given as intramuscular injections. These medications contain a combination of ARTs. An injection is given once a month or every two months—different drugs have different dosing schedules and requirements. Injections require a visit to a healthcare provider’s office. Typically, a person who is treating with a long-acting injectable medication will have started treatment with an oral ART regimen until they achieve viral suppression for at least three months.

Choosing an ART regimen

Different ART regimens will work better for different people. Deciding on what ART medications to use is a decision a person will make with the guidance of a healthcare provider.

Whatever ART regimen you are taking, adherence is the key to success. ART will need to be taken for the duration of a person’s life. Stopping treatment—or even skipping doses or taking medications inconsistently—can lead to drug resistance. Drug resistance can make HIV more difficult to treat.

If you or a loved one is diagnosed with HIV, it is important to partner with a healthcare provider and begin treatment as soon as possible.