Abacavir can cause serious, life-threatening side effects. These include allergic reactions, lactic acidosis (buildup of acid in the blood), and liver problems.
People who take abacavir may have a serious allergic reaction (hypersensitivity reaction) that can cause death. Your risk of this allergic reaction is much higher if you have a gene variation called HLA-B*5701. Your health care provider can determine with a blood test if you have this gene variation. If you get a symptom from two or more of the following groups while taking abacavir, contact your health care provider right away to find out if you should stop taking abacavir.
- Group 1 Symptoms: Fever
- Group 2 Symptoms: Rash.
- Group 3 Symptoms: Nausea, vomiting, diarrhea, abdominal (stomach area) pain.
- Group 4 Symptoms: General ill feeling, extreme tiredness, or achiness.
- Group 5 Symptoms: Shortness of breath, cough, sore throat.
Your pharmacist will give you a Warning Card with a list of these symptoms. Carry this Warning Card with you at all times. If you stop abacavir because of an allergic reaction, never take abacavir or any other abacavir-containing medicine again. If you take abacavir or any other abacavir-containing medicine again after you have had an allergic reaction, within hours you may get life-threatening symptoms that may include very low blood pressure or death. If you stop abacavir for any other reason, even for a few days, and you are not allergic to abacavir, talk with your health care provider before taking it again. Taking abacavir again can cause a serious allergic or life-threatening reaction, even if you never had an allergic reaction to it before. If your health care provider tells you that you can take abacavir again, start taking it when you are around medical help or people who can call a health care provider if you need one.
Contact your health care provider right away if you have any of the following symptoms that may signal lactic acidosis:
- Feeling very weak or tired.
- Unusual (not normal) muscle pain.
- Trouble breathing.
- Stomach pain with nausea and vomiting.
- Feeling cold, especially in your arms and legs.
- Feeling dizzy or lightheaded.
- Fast or irregular heartbeat.
Contact your health care provider right away if you have any of the following symptoms that may signal liver problems:
- Yellowing of your skin or the whites of your eyes (jaundice).
- Dark-colored urine.
- Light-colored bowel movements.
- Loss of appetite for several days or longer.
- Feeling sick to your stomach (nausea).
- Lower stomach area (abdominal) pain.
Abacavir may increase the risk of heart attack (myocardial infarction).
While taking abacavir, it is important to keep all of your appointments with your health care provider.
What is abacavir?
Abacavir is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children 3 months of age and older. Abacavir is always used in combination with other anti-HIV medicines.
Abacavir is a type of anti-HIV medicine called a nucleoside reverse transcriptase inhibitor (NRTI). NRTIs work by blocking HIV reverse transcriptase, an HIV enzyme. This prevents HIV from replicating and lowers the amount of HIV in the blood.
Abacavir does not cure HIV/AIDS. It is not known if abacavir reduces the risk of passing HIV to other people.
What should I tell my health care provider before taking abacavir?
Before taking abacavir, tell your health care provider:
- If you are allergic to abacavir or any other medicines.
- If you have been tested and know whether or not you have a particular gene variation called HLA-B*5701.
- If you have hepatitis B virus (HBV) infection or have other liver problems.
- If you have heart problems, smoke, or have diseases that increase your risk of heart disease, such as high blood pressure, high cholesterol, or diabetes.
- If you have any other medical conditions.
- If you are pregnant or plan to become pregnant. Whether abacavir can harm an unborn baby is unknown.
- If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV or are taking abacavir.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Abacavir may affect the way other medicines or products work, and other medicines or products may affect how abacavir works. Taking abacavir together with certain medicines or products may cause serious side effects.
How should I take abacavir?
Abacavir comes in two forms:
- 300-mg tablets (brand name: Ziagen).
- 20-mg/mL oral solution (a strawberry- and banana-flavored liquid, brand name: Ziagen).
Take abacavir according to your health care provider’s instructions.
Take abacavir with or without food.
Always take abacavir in combination with other anti-HIV medicines.
Children 3 months of age and older can also take abacavir. The child’s health care provider will decide the right dose and whether the child should take the tablet or liquid, based on the child’s weight. The dose should not be more than the recommended adult dose.
If you take too much abacavir, contact your local poison control center (1-800-222-1222) or go to the nearest hospital emergency room right away.
For more information on how to take abacavir, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.)
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose. If you miss several doses of abacavir, call your health care provider before taking abacavir again.
What side effects can abacavir cause?
Abacavir can cause serious, life-threatening side effects. These include allergic reactions, lactic acidosis (buildup of acid in the blood), and liver problems. (See the WARNING above.)
Other possible side effects of abacavir include:
- Changes in the immune system (immune reconstitution inflammatory syndrome).
- Changes in body fat (lipodystrophy).
Tell your health care provider if you have any side effect that bothers you or that does not go away.
These are not all the possible side effects of abacavir. Ask your health care provider or pharmacist for more information on possible side effects of abacavir.
How should abacavir be stored?
- Store abacavir at room temperature, 68°F to 77°F (20°C to 25°C).
- Do not freeze abacavir. Abacavir oral solution may be refrigerated.
- Safely throw away abacavir that is no longer needed or expired (out of date).
- Keep abacavir and all medicines out of reach of children.
Where can I find more information about abacavir?
More information about abacavir is available:
Last Reviewed: February 15, 2013
Last Updated: February 15, 2013