Abacavir/Lamivudine (Abacavir/Lamivudine) for HIV

Abacavir/Lamivudine (abacavir and lamivudine) 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 25 kilograms.

How Abacavir/Lamivudine Works and How It’s Taken

Abacavir/lamivudine is a type of HIV medicine called an antiretroviral. It contains two medicines, abacavir and lamivudine. Both block HIV-1 reverse transcriptase, an enzyme the virus needs to make new copies of itself.

Doctors prescribe Abacavir/lamivudine when treating HIV-1 infection in adults and children who weigh at least 25 kilograms. It is used with other HIV-1 medicines.

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

Abacavir/lamivudine comes as a tablet taken by mouth. It can be taken with or without food.

Typical Dosing for HIV

For adults, the recommended dose is one tablet by mouth once daily with other HIV-1 medicines.

For children who weigh at least 25 kilograms, the recommended dose is also one tablet once daily with other HIV-1 medicines. Before prescribing the tablet, a healthcare provider should make sure the child can swallow it.

Abacavir/lamivudine tablets should not be used in children who weigh less than 25 kilograms.

Each tablet contains a fixed amount of both medicines, so the dose cannot be adjusted. The tablets are not recommended for people with certain kidney or liver problems. People with moderate or severe liver problems should not take Abacavir/lamivudine tablets.

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

Abacavir/Lamivudine Side Effects

In a clinical study of abacavir and lamivudine used with other antiretroviral medicines, the following side effects occurred in at least 5 percent of people in at least one treatment group:

Drug hypersensitivity (allergic reaction)
Insomnia (trouble sleeping)
Depression
Headache or migraine
Fatigue or malaise (tiredness, low energy, or feeling unwell)
Dizziness or vertigo
Nausea
Diarrhea
Rash
Pyrexia (fever)

Serious Side Effects and Warnings

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

Hypersensitivity reaction (serious allergic reaction) — This can involve multiple organs and can be fatal. It often includes fever and/or rash and may also include nausea, vomiting, diarrhea, stomach pain, extreme tiredness, achiness, shortness of breath, cough, or sore throat.
Worsening hepatitis B after stopping treatment — A hepatitis B “flare” can occur in people who also have hepatitis B virus.
Lactic acidosis with severe liver problems — Too much lactic acid can build up in the blood along with an enlarged fatty liver, which can be life-threatening.
Immune reconstitution syndrome — Immune system changes after starting HIV treatment can trigger inflammation from hidden infections. Autoimmune conditions have also been reported.
Myocardial infarction (heart attack) — Some studies have reported heart attacks in people taking abacavir, but the cause is not certain.

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

What To Know Before Taking Abacavir/Lamivudine

Before starting Abacavir/lamivudine, your doctor will test you for a gene variation called HLA-B*5701. People with this gene variation have a higher risk of a serious allergic reaction to abacavir.

Before taking Abacavir/lamivudine, tell your doctor if you have any allergies to Abacavir/Lamivudine or any of its ingredients.

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.

Also tell your doctor if you:

Have been tested for the HLA-B*5701 gene variation
Have or have had liver problems, including hepatitis B or C
Have kidney problems
Have heart problems or smoke
Have high blood pressure, high cholesterol, or diabetes
Are pregnant or plan to become pregnant
Are breastfeeding or plan to breastfeed

Do not take Abacavir/lamivudine if you:

Have the HLA-B*5701 allele
Have ever had a serious allergic reaction to abacavir or lamivudine
Have moderate or severe liver impairment

Do not miss doses or let your supply of Abacavir/lamivudine 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 healthcare provider tells you to take.

A pregnancy registry tracks pregnancy outcomes in people exposed to Abacavir/lamivudine. Healthcare providers can register pregnancies through the Antiretroviral Pregnancy Registry or by calling 800-258-4263.

Do not breastfeed while taking Abacavir/lamivudine. People with HIV-1 should not breastfeed because HIV-1 can pass to a baby through breast milk.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Abacavir/lamivudine for HIV?

In a 48-week study of adults starting HIV treatment, 64 percent to 65 percent of people had a treatment response. About 11 percent had virologic failure, meaning the treatment did not control the virus as planned.

After 48 weeks, the median CD4+ cell count increased by 188 cells per cubic millimeter in the once-daily group and 200 cells per cubic millimeter in the twice-daily group. CD4+ cells are immune cells that HIV can damage.

In a 96-week study of children and teens, 67 percent of those taking abacavir and lamivudine once daily and 70 percent taking it twice daily had HIV-1 levels below 80 copies per milliliter.

Can Abacavir/lamivudine interact with other medicines?

Yes. Abacavir/lamivudine can interact with some medicines and other substances. Tell your healthcare provider about everything you take, including prescription medicines, over-the-counter medicines, vitamins, and herbal supplements.

Some important interactions include:

Methadone — A small number of people may need a higher methadone dose.
Sorbitol — Sorbitol can lower the amount of lamivudine in your body. Long-term use together should be avoided when possible.
Riociguat — Abacavir can raise the amount of riociguat in your body. Your healthcare provider may need to lower the riociguat dose.

Do not start a new medicine without talking to your healthcare provider first.

What tests or monitoring are needed with Abacavir/lamivudine for HIV?

Before starting Abacavir/lamivudine, your healthcare provider should test you for a gene variation called HLA-B*5701. People with this gene variation have a higher risk of a serious allergic reaction to abacavir.

If you have both HIV-1 and hepatitis B, your healthcare provider should closely check your liver for at least several months after you stop Abacavir/lamivudine.

If your kidneys are not working normally and your creatinine clearance stays between 30 and 49 milliliters per minute, your healthcare provider should monitor you for blood problems, such as anemia or low levels of certain white blood cells.