Abacavir can cause serious, life-threatening side effects. These include a serious allergic reaction, lactic acidosis (buildup of lactic acid in the blood), and liver problems.
Serious Allergic Reaction (Hypersensitivity Reaction):
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.
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. (The combination HIV medicines abacavir/lamivudine [brand name: Epzicom] and abacavir/lamivudine/zidovudine [brand name: Trizivir] also contain abacavir.) 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 could be signs of lactic acidosis:
Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:
While taking abacavir, it is important to keep all of your appointments with your health care provider.
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 HIV medicines.
Abacavir belongs to a class (group) of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs). NRTIs block an HIV enzyme called reverse transcriptase. (An enzyme is a protein that starts or increases the speed of a chemical reaction.) By blocking reverse transcriptase, NRTIs prevent HIV from multiplying and can reduce the amount of HIV in the body.
HIV medicines can’t cure HIV/AIDS, but taking a combination of HIV medicines (called an HIV treatment regimen) every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission.
Before taking abacavir, tell your health care provider:
Abacavir comes in two forms, under the 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 HIV medicines.
Children 3 months of age and older can take abacavir. The child’s health care provider will decide the right dose of abacavir based on the child's weight. The dose should not be more than the recommended adult dose. The health care provider will also decide whether the child should take the tablet or liquid form of abacavir.
If you take too much abacavir, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.
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.)
If you miss a dose of abacavir, 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 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.
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:
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. To learn more about possible side effects of abacavir, read the drug label or package insert or talk to your health care provider or pharmacist.
The AIDSinfo fact sheet on HIV Medicines and Side Effects also includes information that may apply to abacavir.
You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online at https://www.accessdata.fda.gov/scripts/medwatch/.
More information about abacavir is available:
Last Reviewed: May 1, 2015