What is abacavir/lamivudine?

Abacavir and lamivudine are medications used to treat HIV. They are antiretroviral drugs combined in one pill. The pill contains 600mg abacavir and 300mg lamivudine. The usual adult dose is one tablet taken once a day along with another antiretroviral drug.

Abacavir/lamivudine is sometimes marketed under the name Kivexa, but generic versions are available.

How does abacavir/lamivudine work?

Abacavir and lamivudine are from a class of drugs known as NRTIs (nucleoside reverse transcriptase inhibitors).

Your doctor will prescribe abacavir/lamivudine as part of your HIV treatment, along with an antiretroviral from another class of drugs. It is important to take all the drugs as prescribed, every day.

Each drug class works against HIV in a different way.

The aim of HIV treatment is to reduce the level of HIV in your body (viral load). Ideally, your viral load should become so low that it is undetectable – usually less than 50 copies of virus per ml of blood. Taking HIV treatment and having an undetectable viral load protects your immune system and stops HIV being passed on to someone else during sex.

How do I take abacavir/lamivudine?

You should take abacavir/lamivudine once a day, with some water. You can take it with or without food.

HIV treatment works best if you take it every day. If you forget to take a dose of abacavir/lamivudine, take it as soon as you remember. If it’s nearly time to take your next dose then don’t take a double dose, just skip the dose you’ve forgotten and carry on.

If you regularly forget to take your treatment, or you aren’t taking it for another reason, it’s important to talk to your doctor about this.

Allergic reaction

Abacavir can cause a serious hypersensitivity (allergic) reaction. This is associated with the presence of a particular gene. Before starting treatment with abacavir/lamivudine (or any other treatment that contains abacavir) you should have a test to see if you have this gene (HLA-B*5701). If the test is positive you must not take abacavir. If the test is negative, it is highly unlikely that an allergic reaction will occur, but contact your HIV clinic immediately (or A&E if out of hours) if you begin to feel unwell after starting the drug.

In the box with the drug there is an ‘alert card’, which you should carry with you for the first six weeks of taking abacavir. The particular side effects you should look out for during this time are:

  • a skin rash

or if you get one or more symptoms from at least two of the following groups:

  • fever
  • shortness of breath, sore throat or cough
  • nausea or vomiting, or diarrhoea or abdominal pain
  • severe tiredness or achiness or generally feeling ill.

You should never retry abacavir, if you have had an allergic reaction to it previously.

What are the possible side effects of abacavir/lamivudine?

All drugs have possible side effects. It’s a good idea to talk to your doctor about possible side effects before you start taking a drug. If you experience something that might be a side effect, talk to your doctor about what can be done. A full list of side effects, including less common side effects, should be included in the leaflet that comes in the packaging with abacavir/lamivudine. See also the section on ‘allergic reaction’ above.

We generally divide side effects into two types:

Common – a side effect that occurs in at least one in a hundred people (more than 1%) who take this drug.

Rare – a side effect that occurs in fewer than one in a hundred people (less than 1%) who take this drug.

The most common side effects of abacavir/lamivudine are hypersensitivity reaction, headache, nausea and vomiting, diarrhoea, stomach pains, loss of appetite, tiredness, lack of energy, fever, general feeling of being unwell, difficulty sleeping, muscle pain and discomfort, joint pain, cough, irritated or runny nose, skin rash, hair loss.

Does abacavir/lamivudine interact with other drugs?

It’s important that your doctor and pharmacist know about any other drugs you are taking. That includes medicine prescribed by another doctor, drugs you have bought from a high-street chemist, herbal and alternative treatments, and recreational drugs.

Some medicines should not be taken together because if they are this can cause serious side effects, or it can stop one or both of the drugs from working. Other drug interactions are less dangerous but still need to be taken seriously. If levels of one drug are affected, you may need to change the dose you take.

A list of drugs, known to have interactions with abacavir/lamivudine, should be included in the leaflet that comes in the packaging with abacavir/lamivudine. Tell your doctor if you are taking any of these drugs, and other drugs that are not on the list.

You should not take abacavir/lamivudine with any of the following drugs:

  • emtricitabine
  • lamivudine
  • high doses of trimethoprim/sulfamethoxazole
  • cladribine.

There are other interactions, including with phenytoin, a drug used to treat epilepsy and methadone, used as a heroin substitute, so it is very important that you tell your doctor about other drugs you are taking.

Can I take abacavir/lamivudine in pregnancy?

If you are considering having a baby, or think you might be pregnant, talk to your doctor as soon as possible about which combination of anti-HIV medications would be right for you. It is important to take antiretroviral treatment during pregnancy to prevent passing HIV from mother to baby.

The manufacturer of abacavir/lamivudine does not recommend its use during pregnancy.


antiretroviral (ARV)

A substance that acts against retroviruses such as HIV. There are several classes of antiretrovirals, which are defined by what step of viral replication they target: nucleoside reverse transcriptase inhibitors; non-nucleoside reverse transcriptase inhibitors; protease inhibitors; entry inhibitors; integrase (strand transfer) inhibitors.

viral load

Measurement of the amount of virus in a blood sample, reported as number of HIV RNA copies per milliliter of blood plasma. Viral load is an important indicator of HIV progression and of how well treatment is working. 


undetectable viral load

A level of viral load that is too low to be picked up by the particular viral load test being used or below an agreed threshold (such as 50 copies/ml or 200 copies/ml). An undetectable viral load is the first goal of antiretroviral therapy.


Any perceptible, subjective change in the body or its functions that signals the presence of a disease or condition, as reported by the patient.



The feeling that one is about to vomit.

However, many women have taken abacavir/lamivudine while pregnant without any problems. The British HIV Association (BHIVA) recommends that women who are already taking anti-HIV medications and become pregnant can usually continue to take the same medication throughout their pregnancy. In addition, BHIVA lists these drugs (in combination with one or two other drugs) as an option that may be recommended for women who start HIV treatment in pregnancy, depending on their individual circumstances.

Women living with HIV are advised not to breastfeed, as HIV can be passed on in breast milk. However, some women do choose to breastfeed. Abacavir/lamivudine should not be used during breastfeeding as at least one of the drugs it contains passes into breast milk.

Can children take abacavir/lamivudine?

Abacavir/lamivudine (600/300mg) can be taken by children weighing 25kg or more.

Talking to your doctor

If you have any concerns about your treatment or other aspects of your health, it’s important to talk to your doctor about them.

For example, if you have a symptom or side effect or if you are having problems taking your treatment every day, it’s important that your doctor knows about this. If you are taking any other medication or recreational drugs, or if you have another medical condition, this is also important for your doctor to know about.

Building a relationship with a doctor may take time. You may feel very comfortable talking to your doctor, but some people find it more difficult, particularly when talking about sex, mental health, or symptoms they find embarrassing. It’s also easy to forget things you wanted to talk about.

Preparing for an appointment can be very helpful. Take some time to think about what you are going to say. You might find it helpful to talk to someone else first, or to make some notes and bring them to your appointment. 

For detailed information on this drug, visit the abacavir/lamivudine page in the A-Z of antiretroviral medications.

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