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Abacavir is used to treat HIV. It works by helping stop the spread of HIV in your body. Nausea is a common side effect but can be a symptom of a severe allergic reaction. This medicine needs to be stopped right away and never taken again if you get certain symptoms. Read the Medication Guide that comes with abacavir, and carry the Warning card given to you.

Uses

What is abacavir used for?

Abacavir is commonly used with other medicines to treat HIV.

Abacavir may also be used for other conditions as determined by your health care provider.

How does abacavir work (mechanism of action)?

Abacavir works to help stop the spread of HIV in your body. This medicine inhibits an enzyme that HIV needs to make more copies of itself. A lower amount of HIV in your body helps protect and preserve the immune system.

How is abacavir supplied (dosage forms)?

Brands and other names

  • Ziagen

Dosage forms and strengths

  • 300 mg oral tablets
  • 20 mg/mL oral solution

How should I store abacavir?

Abacavir should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). It can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. The oral solution may be kept in the refrigerator, but do not freeze the solution. 

Side Effects

What are the most common side effects of abacavir?

The most common side effects of abacavir are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Nausea and vomiting
  • Headache
  • General feeling of being unwell, tired, or not having your usual energy
  • Sleep problems
  • Skin rashes
  • Fever and chills
  • Infection in the nose, throat, or ear

There may be other side effects of abacavir that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of abacavir?

While less common, the most serious side effects of abacavir are described below, along with what to do if they happen.

Severe Allergic Reactions. Abacavir may cause allergic reactions, which can be serious. Stop taking abacavir and get help right away if you have any of the following symptoms of a serious allergic reaction. Do not ever take this medicine again or any medicine that has abacavir if you get a severe allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Extreme tiredness or achiness
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Cough or sore throat
  • Shortness of breath
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea, vomiting, or diarrhea
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps or pain
  • Joint pain

Lactic Acidosis. Abacavir may cause lactic acidosis (a buildup of lactic acid in your blood), which can be serious. Stop taking abacavir and get help right away if you have any of the following symptoms of lactic acidosis.

  • General ill feeling
  • Muscle pain
  • Difficulty breathing
  • Drowsiness or dizziness
  • Stomach pain, nausea, or vomiting
  • Feel cold, especially in your legs and arms

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking abacavir. Call your health care provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Immune System Changes. When you start abacavir, your immune system might get stronger and start fighting infections that have been hiding inside your body for a long time. The type of symptoms you may have will depend on the infection. Tell your health care provider right away if you notice any of the following new symptoms of infection.

  • Fever, sweats, chills, or muscle aches
  • Swollen lymph nodes
  • Vision problems
  • Confusion, problems talking, or headache
  • Skin problems such as a painful rash or warts
  • Cough or coughing up blood
  • Weakness or coordination problems

Heart Attack. Abacavir may increase your risk of having a heart attack. Talk with your health care provider about your risk for heart disease before taking abacavir. Get emergency help if you have any of the following symptoms of a heart attack.

  • Chest pain or pressure
  • Fast or abnormal heartbeat
  • Trouble breathing
  • Pain in your back, jaw, throat, or arm
  • Sweating, upset stomach, vomiting, or dizziness

Warnings & Precautions

Who should not use abacavir?

Allergies to Ingredients. People who are allergic to any of the following should not take abacavir.

  • Abacavir
  • Ziagen
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific abacavir products they stock.

Genetic Variation. People with a certain genetic variation, known as the HLA-B*5701 allele, should not take abacavir. These people are at a higher risk of a severe allergic reaction from abacavir.

Liver Problems. Abacavir should not be used if your liver is not working as well as it should be. If there is a concern about the health of your liver, your health care provider may do tests to determine if it is working well enough to take this medicine.

What should I know about abacavir before using it?

Do not take abacavir unless it has been prescribed to you by a health care provider. Take it as prescribed.

Each time you get this medicine from the pharmacy, you need to get a copy of the Medication Guide and a Warning card. If you do not get both, ask your pharmacist. Keep the Warning card with you at all times, and read the Medication Guide each time because new information may be present. Both documents have information about how to tell if you get a severe allergic reaction.

Do not share abacavir with other people, even if they have the same condition as you. It may harm them.

If you are taking the oral solution, use an accurate measuring device to measure your dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist to recommend an appropriate measuring device.

Keep abacavir out of the reach of children. As abacavir oral liquid may be kept in a refrigerator, take special precautions to keep it away from children who also use the refrigerator.

Your health care provider will likely test for a genetic variation, known as the HLA-B*5701 allele, before starting abacavir. This is to make sure you are not at a higher risk of a severe allergic reaction.

While abacavir can help keep the HIV infection under control, it does not cure it. Abacavir does not help protect against or prevent the spread of sexually transmitted infections (STI), like herpes, gonorrhea, or chlamydia.

What should I tell my health care provider before using abacavir?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if abacavir is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Liver problems, including hepatitis B or C
  • Heart disease
  • High blood pressure
  • High cholesterol
  • Diabetes
  • Smoke 

Other Medicines and Supplements. Abacavir may interact with other medicines and supplements. Before taking abacavir, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how abacavir could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will advise you if you should take abacavir while you are pregnant or trying to get pregnant. If you become pregnant while taking abacavir, you can register for the Antiretroviral Pregnancy Registry by visiting www.apregistry.com. This registry collects safety information about the use of antiretroviral medicines during pregnancy.

Breastfeeding. Abacavir passes into breast milk. Do not breastfeed while taking abacavir. There may be risks with breastfeeding while taking abacavir and having HIV.

Interactions

Does abacavir interact with foods or drinks?

There are no known interactions between abacavir and foods or drinks.

Do not drink alcohol or take other medicines that contain alcohol while taking abacavir. Drinking alcohol while taking abacavir may increase the risk of side effects from the medicine. 

Does abacavir interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking abacavir.

  • Methadone, which is an opioid medicine used to treat pain or opioid use disorder
  • Riociguat (Adempas), which is a medicine used to treat pulmonary hypertension
  • A medicine for HIV or AIDS

This may not be a complete list of medicines that can interact with abacavir. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much abacavir?

If you or someone else has used too much abacavir, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of abacavir?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

Missing doses of abacavir can cause it not to work as well over time. It is very important not to miss or skip doses. If you stop this medicine for any reason, do not restart it without talking with your health care provider. You may have a life-threatening reaction even if you had no problem taking it before.