Antiretroviral therapy (ART) uses a combination of drugs to reduce the amount of HIV in the body. When a person takes them consistently, these drugs are very effective at limiting the effects of the virus.

Although inequities exist by region and population, advances in ART have made it possible for many people with HIV to live a life span comparable to those without HIV.

ART helps keep the body healthy and prevents symptoms from progressing. When a person follows this regimen as prescribed, it may also keep them from transmitting the virus to others.

The Centers for Disease Control and Protection (CDC) recommend all people living with HIV undergo this therapy, regardless of how long they have had the virus or how healthy they are currently. Over the past few years, ART has become more potent, less toxic, and easier to use. It creates fewer side effects than it once did, and they are less severe.

This article explores the differences between common antiretroviral drugs and outlines how they work, including their potential side effects. It also provides information about beginning treatment.

Following an ART regimen involves taking a combination of drugs each day. This usually involves at least three different drugs from at least two drug classes.

Below are some of the classes of HIV treatment drugs.

Nucleoside reverse transcriptase inhibitors

Nucleoside reverse transcriptase inhibitors (NRTIs) block the action of an enzyme called reverse transcriptase, which HIV needs to replicate.

Some examples of NRTIs include:

  • abacavir (Ziagen)
  • emtricitabine (Emtriva)
  • lamivudine (Epivir)
  • tenofovir disoproxil fumarate (Viread)
  • zidovudine (Retrovir)

Non-nucleoside reverse transcriptase inhibitors

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) bind to reverse transcriptase and prevent HIV from replicating.

Some examples of NNRTIs include:

  • doravirine (Pifeltro)
  • efavirenz (Sustiva)
  • etravirine (Intelence)
  • rilpivirine (Edurant)

Protease inhibitors

Protease inhibitors (PIs) impede another enzyme called HIV protease. HIV also requires protease to replicate.

Some types of PI include:

  • atazanavir (Reyataz)
  • darunavir (Prezista)
  • fosamprenavir (Lexiva)
  • ritonavir (Norvir)
  • tipranavir (Aptivus)

Entry inhibitors

As the name suggests, these drugs prevent HIV from entering targeted cells. HIV must bind to cells’ proteins to penetrate immune cells, and these drugs keep this from happening.

People often take entry inhibitors when other treatments have not worked.

Examples currently in use include enfuvirtide (Fuzeon) and maraviroc (Selzentry).

Integrase inhibitors

HIV uses an enzyme called integrase to send its genetic material into the cells’ DNA. Integrase inhibitors block this action.

Research into these drugs is ongoing, but some currently approved types include dolutegravir (Tivicay) and raltegravir (Isentress).

HIV is a retrovirus. Antiretroviral therapy combats HIV by lowering amounts of the virus in the body.

A retrovirus spreads by working its way into the body’s host cells and making copies of itself, which then keep replicating. Over time, the virus can decimate a person’s immune system.

To treat HIV, experts recommend combination antiretroviral therapy (cART). It usually involves two or more drugs from these classes:

  • NRTI: nucleoside reverse transcriptase inhibitors
  • NNRTI: non-nucleoside reverse transcriptase inhibitors
  • PI: protease inhibitors
  • INSTI: integrase strand transfer inhibitors

cART helps prevent complications of HIV. The side effects tend to be manageable, but serious side effects can occur in rare cases.

Using ART stops HIV from progressing. It keeps the virus from multiplying, which allows the body to generate more helpful white blood cells.

Although ART cannot remove HIV from the body, it can keep the immune system strong enough to fend off infections and some HIV-related cancers.

ART does this by reducing the amount of HIV in the blood to very low levels. Viral suppression occurs when a person’s count reaches fewer than 200 copies of the virus per milliliter of blood.

When the viral load is so low that it is undetectable, it no longer damages the immune system, and there is no risk of spreading the virus to others. Public health campaigns refer to this as “undetectable = untransmittable.”

Most people using antiretroviral drugs reach viral suppression within 6 months.

Antiretroviral drugs can have adverse effects. Most are manageable, but some can be serious. Newer drugs tend to cause fewer and less severe side effects.

The benefits of taking HIV medication typically outweigh the side effects. These treatments can help people live long, healthy lives with a reduced risk of HIV-related complications and transmission.

Potential side effects vary depending on the type of medication a person uses. Sometimes, the same medication will produce different side effects in different people.

Short-term side effects of ART, such as nausea or fatigue, may last only a few days or weeks. Other side effects, such as high cholesterol, may not appear for a few months or years.

The possible side effects of ART include:

People who experience severe or lasting side effects should talk with a healthcare professional about changing their dosage or finding a new drug combination that works better for them.

Those who wish to stop taking the medication should speak to a healthcare professional first. Having a break from ART can cause HIV to multiply rapidly, increasing the risk of illness and infection.

Some long-term side effects of ART may include:

Side effects that point to more serious complications and a possible need for urgent care include:

People who experience facial, throat, or tongue swelling require emergency treatment. They should call an ambulance or go to the nearest emergency room if this occurs.

Managing side effects

Healthcare professionals can provide support to people experiencing side effects from ART. When symptoms are severe or ongoing, they may recommend alternative medications.

Anyone considering ART should discuss their lifestyle, needs, preferences, and current health status with a healthcare professional, who will take these factors into account when creating a treatment plan.

Antiretroviral drugs can interact with a variety of substances, including:

People taking ART should tell a healthcare professional about other medications and supplements they are taking, as these can influence how the treatment works. Some combinations cause adverse reactions.

Certain HIV drugs may also make hormonal birth control less effective. People who take this type of birth control may want to investigate using a different method to prevent pregnancy.

In most cases, ART is safe to use while undergoing hormonal therapy, although it can cause some side effects. As a result, people should speak with a healthcare professional to discuss the potential effects of ART on their hormone therapy and stay in regular contact to discuss any side effects should they occur.

As noted above, the CDC recommends that all people living with HIV use ART, regardless of how long they have had the virus or how healthy they are currently.

That includes the following groups:

  • people in the early stages of HIV
  • people who are pregnant
  • people living with AIDS
  • people with HIV-related infections or cancers

Ideally, someone would begin ART the day they get a positive HIV test or as soon as possible afterward. This would give them the best chance of lowering their viral load, avoiding complications, and preventing transmission.

People who do not receive proper treatment with ART typically develop stage 3 HIV, or AIDS, within 10 years. Their immune systems are very damaged at that point, rendering them vulnerable to infections or certain types of cancer.

Maintaining a daily treatment plan can be challenging for some people. Reasons for this may include:

  • inability to pay for medications
  • lack of access to treatment
  • discrimination within the healthcare system
  • mental health and substance use issues
  • pill fear or pill fatigue

People who have difficulty following an ART regimen should consult a healthcare professional who can work with them to find an appropriate solution.

There are resources to help people cover the costs of HIV treatment and follow an ART regimen.

Antiretroviral drugs are effective treatments for HIV. Organizations worldwide recommend that everyone who tests positive for the virus begin antiretroviral therapy (ART) as soon as possible.

ART can reduce the risk of HIV-related complications, stop the virus from progressing, and help prevent further transmission. It can also increase a person’s quality of life and life expectancy.

People sometimes experience side effects with ART. Some of these should resolve after a few days or weeks of treatment. If they do not, a healthcare professional may need to prescribe different medications.

Healthcare professionals can provide more information on ART and guidance on specific treatment options.