Lamivudine is a medication used to treat HIV, originally marketed under the brand name Epivir. Several companies now make generic versions of lamivudine. It is taken in combination with other antiretroviral drugs.

The usual adult dose of lamivudine is 300mg per day. You could take one 300mg tablet once a day, or one 150mg tablet twice a day.

Lamivudine is also available in combination tablets. Several companies make a pill which contains lamivudine and another drug, abacavir, in one pill. This was originally marketed under the brand name Kivexa, but generic versions are now available. Lamivudine and zidovudine are also available in a combination pill, originally marketed as Combivir.

Lamivudine is also available in a single-tablet regimen, which means all the drugs for combination antiretroviral therapy in one pill. This is a pill which contains lamivudine, abacavir and dolutegravir, marketed as Triumeq.

Lamivudine is from a class of drugs known as nucleoside reverse transcriptase inhibitors (NRTIs). Your doctor will prescribe lamivudine as part of your HIV treatment, along with antiretrovirals 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.

You can take lamivudine with or without food.

You can take it with some water, or if you have difficulty swallowing the pills, you can crush them and take them with food or water. It’s very important to take the whole dose, so if you do crush a pill, make sure you take all of it.

HIV treatment works best if you take it every day. When would be a good time for you to plan to take your treatment? Think about your daily routine and when you will find it easiest to take your treatment.

If you forget to take a dose of lamivudine, take it as soon as you remember. If it is nearly time for 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.

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 lamivudine.

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 lamivudine include:

Headache, feeling sick, being sick, diarrhoea, stomach pains, tiredness, lack of energy, fever (high temperature), general feeling of being unwell, muscle pain and discomfort, joint pain, difficulty in sleeping (insomnia), cough, irritated or runny nose, rash, hair loss (alopecia).

Rare side-effects of lamivudine include: lactic acidosis, liver damage.

You should always tell your doctor and pharmacist about any other drugs or medication you are taking. That includes anything prescribed by another doctor, medicines you have bought from a high-street chemist, herbal and alternative treatments, and recreational or party drugs (‘chems’).

Some medicines or drugs are not safe if taken together – the interaction could cause increased, dangerous levels, or it could 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. This must only be done on the advice of your HIV doctor.

Any drugs that are known to have interactions with lamivudine will be listed in the leaflet that comes in the packaging with 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 lamivudine if you are taking any of these drugs:

• emtricitabine, another antiretroviral drug
• high doses of the antibiotic cotrimoxazole
• cladribine, used to treat a type of blood cancer called hairy cell leukaemia.

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 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 lamivudine (in combination with other medications) 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. Lamivudine should not be used during breastfeeding as a small amount of the drug passes into breast milk.

Lamivudine is approved for use in children. A liquid suspension is available.

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. Our online tool Talking points may help you to prepare for your next appointment – visit www.aidsmap.com/talking-points 

For detailed information on this drug, visit the lamivudine pages in the A-Z of antiretroviral drugs..