Nucleoside/Nucleotide Reverse Transcriptase Inhibitors for HIV

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Nucleoside/Nucleotide Reverse Transcriptase Inhibitors for HIV


Generic NameBrand Name
didanosine, also known as dideoxyinosine, ddIVidex
lamivudine (3TC)Epivir
stavudine (d4T)Zerit
zidovudine (ZDV), formerly known as azidothymidine (AZT)Retrovir

Combination medicines

Generic NameBrand Name
abacavir and lamivudineEpzicom
abacavir, lamivudine, and zidovudineTrizivir
emtricitabine and tenofovirTruvada
emtricitabine, efavirenz, and tenofovirAtripla
emtricitabine, rilpivirine, and tenofovirComplera
lamivudine and zidovudineCombivir
cobicistat, elvitegravir, emtricitabine, and tenofovirStribild

These medicines may be available in other combinations to treat HIV infection.

How It Works

Nucleoside/nucleotide reverse transcriptase inhibitors are antiretroviral medicines. They prevent the human immunodeficiency virus (HIV) from multiplying. When the amount of virus in the blood is kept at a minimum, the immune system has a chance to recover and grow stronger.

Why It Is Used

The use of three or more antiretroviral medicines (antiretroviral therapy, or ART) is the usual treatment for HIV infection.

The combination of medicines used for ART will depend on your health, other conditions you might have (such as hepatitis), and results of testing. Talk to your doctor about the best treatment plan for you.

Medical experts recommend that people begin treatment for HIV as soon as they know that they are infected.1, 2 Treatment is especially important for pregnant women, people who have other infections (such as tuberculosis or hepatitis), and people who have symptoms of AIDS.

You may also want to start HIV treatment if your sex partner does not have HIV. Treatment of your HIV infection can help prevent the spread of HIV to your sex partner.3

If you do not have HIV, you can take the combination medicine Truvada (tenofovir plus emtricitabine) every day to help protect yourself against getting infected. But you still need to use safer sex practices to keep your risk low.4

The U.S. National Institutes of Health recommends one of the following programs for people who begin treatment for HIV:3

  • Efavirenz + tenofovir + emtricitabine
  • Ritonavir-boosted atazanavir + tenofovir + emtricitabine
  • Ritonavir-boosted darunavir + tenofovir + emtricitabine
  • Raltegravir + tenofovir + emtricitabine
Click here to view a Decision Point.HIV: When Should I Start Antiretroviral Medicines for HIV Infection?
Click here to view an Actionset.HIV: Taking Antiretroviral Drugs

Zidovudine (ZDV), either alone or in combination with other antiretrovirals, is recommended for HIV-infected women who are more than 12 weeks pregnant, to prevent HIV from spreading to the fetus. The baby should also receive treatment for 6 weeks after birth.

How Well It Works

Combination therapy:

  • Reduces viral loads, which can lead to stable or increased CD4+ cell counts, a sign that the immune system is still able to fight off opportunistic infections.
  • Decreases the number and severity of opportunistic infections.
  • Reduces or prevents resistance to the medicines.
  • Prolongs life.

Antiretroviral therapy can also reduce symptoms of HIV infection, such as fever, weakness, and weight loss.

Zidovudine (ZDV), either alone or in combination with other antiretrovirals, reduces the risk of the spread of HIV from an infected mother to her baby.3

And studies have shown that if you are not infected with HIV, taking antiretroviral medicines can protect you against HIV.4, 5, 6 But to keep your risk low, you still need to use safer sex practices.

The rate at which antiretrovirals decrease viral loads is affected by:3

  • CD4+ cell counts at the beginning of treatment.
  • Viral load at the beginning of treatment.
  • The dosage of the medicines.
  • Whether the medicines are taken exactly as prescribed.
  • Whether antiretroviral medicines have been taken before.
  • Whether any opportunistic infections are present.

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

  • Trouble breathing.
  • Swelling of your face, lips, tongue, or throat.

Call your doctor if you have:

  • Hives.

Side effects of these medicines include:

  • Headache.
  • Changes in the distribution of body fat.
  • Nausea, vomiting, and diarrhea.
  • Numbness, tingling, and painful sensations in the hands and feet (peripheral neuropathy).
  • Severe fatigue.
  • Kidney problems.

A serious, potentially life-threatening allergic reaction occurs in a small number of people who take abacavir. A screening test (HLA-B*5701 test) is available to help predict who may have a serious reaction to abacavir.7 The U.S. Department of Health and Human Services (DHHS) recommends that anyone who may receive abacavir should get tested for sensitivity to it first.3

Didanosine may cause inflammation of the pancreas (pancreatitis). This can lead to belly pain and vomiting. This side effect is more common in people who drink alcohol heavily. In rare cases, didanosine can also cause serious liver damage.

In rare cases emtricitabine causes severe liver problems.

People who are infected with hepatitis B may have a flare-up of the illness if they suddenly stop taking certain nucleoside/nucleotide reverse transcriptase inhibitors.

Side effects of any combination medicine can include the side effects of any of the single medicines in the combination.

Report all side effects to your doctor at your next visit. He or she can adjust your dose or give you other medicines to reduce side effects. Some mild side effects, such as nausea, improve as your body adjusts to the medicine.

Many people think that antiretroviral medicines always have severe side effects. In fact, only a few people experience severe side effects.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Factors to consider when choosing a combination of medicines include:

  • The ability of the medicines to reduce your viral load.
  • The likelihood that the virus will develop resistance to a certain class of medicine. If you have already been treated with an antiretroviral medicine, you may already know whether you are resistant to medicines in that class.
  • Side effects and your willingness to tolerate them.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.



  1. U.S. Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents (2012). Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents. Available online:
  2. Thompson MA, et al. (2012). Antiretroviral treatment of adult HIV infection: 2012 recommendations of the International Antiviral Society—USA Panel. JAMA, 308(4): 387–402.
  3. U.S. Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents (2011). Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents. Available online:
  4. Baeten JM, et al. (2012). Antiretroviral prophylaxis for HIV prevention in heterosexual men and women. New England Journal of Medicine, 367(5): 399–410.
  5. Grant RM, et al. (2010). Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. New England Journal of Medicine, 363(27): 2588–2599.
  6. Thigpen MC, et al. (2012). Antiretroviral preexposure prophylaxis for heterosexual HIV transmission in Botswana. New England Journal of Medicine, 367(5): 423–434.
  7. Mallal S, et al. (2008). HLA-B*5701 screening for hypersensitivity to abacavir. New England Journal of Medicine, 358(6): 568–579.


ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerPeter Shalit, MD, PhD - Internal Medicine
Last RevisedNovember 7, 2012

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