Medication Information Leaflet

What is this medication for?

Abacavir is an antiretroviral medication used for treating human immunodeficiency virus (HIV) infection. It works by preventing the virus from reproducing, and hence, reducing the amount of virus in your body. This increases the CD4 cell count in your body. CD4 cells are a type of immune cells that help your body fight off infections. 

Abacavir is not a cure for HIV infection. It must be taken consistently every day to slow the progression of the disease.

How should I take/use this medication?

  • Abacavir is always given in combination with other antiretroviral medication. Do not stop taking your medication without consulting checking with your healthcare professional. 
  • It is important to take the antiretroviral combination therapy exactly as prescribed every day.
  • Do not miss any doses as this may make the medication less effective.
  • You may take this medication with or without food. 

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose. 

What precautions should I take?

Inform your healthcare professional if: 

  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding 
  • You are taking any other medications, including supplements, traditional medications and herbal remedies
  • You have heart problems, smoke or have a medical condition that increases your risk of heart disease such as high blood pressure, high cholesterol, or diabetes

What are some common side-effects of this medication?

  • Headache
    • Mild painkiller (Paracetamol) can be taken to reduce the pain
  • Tiredness
  • Nausea or vomiting
    • Try taking Abacavir with or after food 
    • Avoid foods with high fat content and eat small frequent meals 
    • Try sucking on hard candy to reduce the nausea feeling 
  • Dreams/sleep disorders such as bad dreams

Inform your healthcare professional if these side effects persist or are intolerable.

What are some rare but serious side-effects that I need to seek medical advice immediately?

Abacavir can cause a serious allergy reaction known as Abacavir-associated hypersensitivity reaction. This is characterised by:

  • Fever
  • Rash
  • Gastrointestinal symptoms (including nausea, vomiting, diarrhoea, or stomach pain)
  • Flu-like symptoms
  • Extreme tiredness or achiness
  • Shortness of breath
  • Cough
  • Sore throat

It can occur any time during the treatment with Abacavir but is more likely during the first 6 weeks of treatment initiation. If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately. You are more likely to develop a hypersensitivity reaction to Abacavir if you have the HLA-B*5701 gene. If you have been tested positive for this gene, your physician will not commence you on Abacavir therapy.

Rarely, Abacavir can cause a build-up of acid in your blood (lactic acidosis). Consult your doctor if you experience signs of lactic acidosis such as:

  • Fast breathing or shortness of breath
  • Fast or irregular heartbeat
  • Dizziness or light-headedness
  • Stomach discomfort
  • Nausea or vomiting
  • Extreme tiredness or weakness
  • Muscle pain or cramps

Liver problem can occur in people taking Abacavir. Consult your doctor if you experience signs of liver problem such as:

  • Yellowing of the skin and eye white
  • Dark-coloured urine
  • Light-coloured stools
  • Loss of appetite
  • Nausea
  • Pain on the right side of the stomach

A higher chance of heart attack was seen in people who took Abacavir. It is not known if this effect is caused by Abacavir. Seek medical consult immediately if you experience signs of heart attack such as:

  • Pressure or tightness of the chest
  • Chest pain that radiates to the left arm, back or neck region
  • Shortness of breath
  • Cold sweat
  • Nausea or vomiting 

What food or medication should I avoid when I take this medication?

Not applicable 

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack the medication into a bag and bring it back to the pharmacy where you received the medication from.


Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on August 2023

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