Lamivudine/Zidovudine (Lamivudine and Zidovudine) for HIV

Lamivudine/Zidovudine (lamivudine and zidovudine) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to treat human immunodeficiency virus type 1 (HIV-1) infection in adults and children who weigh at least 30 kilograms.

How Lamivudine/Zidovudine Works and How It’s Taken

Lamivudine/Zidovudine contains two medicines, lamivudine and zidovudine. Both are antiretroviral medicines used to treat HIV-1 infection.

These medicines block reverse transcriptase, an enzyme HIV uses to make copies of its genetic material.

Doctors prescribe Lamivudine/Zidovudine when treating HIV-1 infection, along with other antiretroviral medicines.

HIV-1 is the virus that causes acquired immune deficiency syndrome (AIDS).

Lamivudine/Zidovudine comes as a tablet taken by mouth.

Typical Dosing for HIV

Adults and adolescents who weigh at least 30 kilograms — 1 tablet by mouth twice daily
Children who weigh at least 30 kilograms and can swallow tablets — 1 tablet by mouth twice daily

Each tablet contains 150 milligrams of lamivudine and 300 milligrams of zidovudine.

Before Lamivudine/Zidovudine is prescribed for a child, the healthcare provider should make sure the child can reliably swallow the tablet. If the child cannot swallow tablets, the healthcare provider may prescribe liquid forms of lamivudine and zidovudine instead.

Lamivudine/Zidovudine tablets are not recommended for children who weigh less than 30 kilograms. They are also not recommended for people with certain kidney or liver problems or for people who need a lower dose because of side effects.

This information is based on prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Lamivudine/Zidovudine Side Effects

In clinical studies of lamivudine plus zidovudine used with other HIV medicines to treat HIV-1 infection, the most common side effects occurred in about 18 percent to 35 percent of people. These included:

Headache
Nausea
Malaise (feeling unwell) or fatigue (tiredness)
Nasal signs and symptoms, such as a runny or stuffy nose
Diarrhea
Cough

Serious Side Effects and Warnings

Lamivudine/Zidovudine can cause serious side effects that may require immediate medical attention. These include:

Anemia and neutropenia — These involve low levels of red blood cells or certain white blood cells. Neutropenia can increase the risk of infections.
Myopathy or myositis — These conditions can cause muscle weakness or muscle inflammation, especially with long-term use.
Lactic acidosis with severe liver problems — This is a dangerous buildup of lactic acid in the blood, sometimes with an enlarged fatty liver.
Hepatitis B flare after stopping treatment — Liver inflammation can worsen in people who also have hepatitis B.
Pancreatitis — This is inflammation of the pancreas.
Immune reconstitution syndrome — New or worsening inflammation can occur as the immune system gets stronger, sometimes revealing hidden infections or triggering autoimmune conditions.
Lipoatrophy — This is loss of fat under the skin, often in the face, arms, legs, or buttocks.
Severe allergic reactions — These can include anaphylaxis, which can cause trouble breathing, swelling, or hives.

Get medical help right away if you think you are having a serious reaction.

What To Know Before Taking Lamivudine/Zidovudine

Do not take Lamivudine/Zidovudine if you have had an allergic reaction to lamivudine or zidovudine.

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements. Some medicines can interact with Lamivudine/Zidovudine.

Do not miss doses or let your supply of Lamivudine/Zidovudine run out. The amount of virus in your blood may increase, and the virus may become harder to treat.

If you miss a dose, take it as soon as you remember. Do not take two doses at the same time or take more than your prescribed dose.

If you are pregnant, tell your healthcare provider. The Antiretroviral Pregnancy Registry tracks pregnancy outcomes in people exposed to lamivudine and zidovudine.

Healthcare providers can register pregnancies by calling 800-258-4263. For more information, visit the Antiretroviral Pregnancy Registry.

Do not breastfeed if you have HIV-1 and are taking Lamivudine/Zidovudine. HIV-1 can pass to a baby through breast milk. Lamivudine and zidovudine are also found in breast milk.

Breastfeeding may:

Pass HIV-1 to a baby who does not have HIV-1
Make HIV-1 harder to treat in a baby who has HIV-1
Cause side effects in the baby similar to those seen in adults

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Lamivudine/Zidovudine for HIV?

Lamivudine/Zidovudine is used with other antiretroviral medicines to treat HIV-1.

In a study of 1,816 adults with HIV-1, researchers looked at what happened when lamivudine was added to the HIV treatment people were already taking. Over a median of 12 months, HIV-1 disease progression or death occurred in 9.6 percent of people who received lamivudine plus their current treatment, compared with 19.6 percent of people who stayed on their current treatment alone.

Deaths occurred in 2.6 percent of people who received lamivudine plus their current treatment, compared with 5.9 percent of people who received their current treatment alone.

How long does Lamivudine/Zidovudine take to work for HIV?

The study does not give an exact amount of time for Lamivudine/Zidovudine to start working. In the main adult study, people were followed for a median of 12 months. This does not mean the medicine takes 12 months to work.

Separately, the prescribing information reports that HIV-1 from most people treated with lamivudine alone or with lamivudine plus zidovudine became resistant to lamivudine within 12 weeks.

Can Lamivudine/Zidovudine interact with other medicines?

Yes. Lamivudine/Zidovudine can interact with some medicines.

Zidovudine should be avoided with certain medicines because they may work against it. These include:

Stavudine
Doxorubicin
Nucleoside analogs such as ribavirin

Some medicines may also increase the risk of blood problems from zidovudine. These include:

Ganciclovir
Interferon alfa
Ribavirin
Other medicines that can affect the bone marrow or blood cells

Sorbitol can lower the amount of lamivudine in the body. When possible, sorbitol-containing medicines should be avoided with lamivudine-containing medicines.

Talk with your healthcare provider about the medicines you take before starting Lamivudine/Zidovudine.