Abacavir

(a ba ka' vir)

Brand Name(s): Ziagen^®, Epzicom^® (as a combination product containing Abacavir, Lamivudine)¶; also available generically

IMPORTANT WARNING:

Abacavir may cause a serious or life-threatening allergic reaction. Call your doctor immediately if you develop one symptom from two or more of the following groups to see if you should stop taking abacavir:

• Group 1: fever
• Group 2: rash
• Group 3: nausea, vomiting, diarrhea, or stomach area pain
• Group 4: generally ill feeling, extreme tiredness, or achiness
• Group 5: shortness of breath, cough, or sore throat

Your pharmacist will give you a Warning Card when you receive your medication. The Warning Card contains a list of the symptoms above. Carry the card with you.

Some people may be more likely to have an allergic reaction to abacavir based on their heredity. Your doctor will order a lab test to determine if you are more likely to have an allergic reaction to abacavir.

Tell your doctor and pharmacist if you are allergic to abacavir or any other medications that contain abacavir.Do not take this medication if you have had a previous allergic reaction to abacavir or any other medication containing abacavir.

If your doctor tells you to stop taking abacavir because you had an allergic reaction, never take abacavir or a medication containing abacavir again. If you stop taking abacavir for any other reason, do not start taking it again without first talking to your doctor. You will need to be around people who can provide or call for emergency medical care, if needed, when you restart this medication.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to abacavir.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) and a Warning Card when you begin treatment with abacavir and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (https://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer's website to obtain the Medication Guide and Warning Card.

Talk to your doctor about the risks of taking abacavir.

WHY is this medicine prescribed?

Abacavir is used to treat human immunodeficiency virus (HIV) infection.Abacavir is in a class of medications called nucleoside reverse transcriptase inhibitors (NRTIs). It works by decreasing the amount of HIV in the blood.

Although abacavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses.Taking these medications and making other lifestyle changes may decrease the risk of giving the HIV virus to other people.

Are there OTHER USES for this medicine?

Abacavir is also used to prevent HIV infection in people who have been exposed to it. Talk to your doctor about the possible risks of using this medication for your condition.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Abacavir comes as a tablet and a solution (liquid) to take by mouth. It is usually taken once or twice daily with or without food. Take abacavir at around the same time(s) every day.

Take abacavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Abacavir helps to control HIV infection but does not cure it. Continue to take abacavir even if you feel well. Do not stop taking abacavir without talking to your doctor. If you stop taking abacavir or skip doses, your condition may become more difficult to treat, or you could have an allergic reaction when restarting the medication (See Important Warning section).

What SPECIAL PRECAUTIONS should I follow?

Before taking abacavir,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any otherdrugs, foods or substances. Tell your doctor or pharmacist about the allergy and whatsymptoms you had

• Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking abacavir. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

• in addition to the condition listed in the IMPORTANT WARNING section, tell your doctor if you smoke or if you have or have ever had any type of infection that does not go away or that comes and goes such as tuberculosis (TB; a type of lung infection) or cytomegalovirus (CMV; a viral infection that may cause symptoms in patients with weak immune systems), depression, diabetes, high blood pressure, high cholesterol, or liver or heart disease.

• tell your doctor if you are pregnant, or plan to become pregnant. If you become pregnant while taking abacavir, call your doctor.

• tell your doctor if you are breastfeeding or plan to breastfeed. Some of the medication and HIV may be passed to your baby in your breast milk. Talk to your doctor about the risks of breastfeeding your baby if you are taking abacavir.

• talk to your doctor about the safe use of alcohol while taking this medication.

• you should know that while you are taking medications to treat HIV infection, your immune system may get stronger and begin to fight other infections that were already in your body, such as pneumonia, herpes virus, tuberculosis, hepatitis, or a fungal infection. If you have new symptoms after starting treatment with abacavir, be sure to tell your doctor.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.If you miss several doses of abacavir, call your doctor before starting to take this medication again. (See Important Warning section).

What SIDE EFFECTS can this medicine cause?

Abacavir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• tiredness
• nausea, vomiting
• difficulty falling asleep or staying asleep

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

• hives, itching, blisters or peeling skin, difficulty swallowing or breathing
• excessive tiredness; weakness, dizziness or lightheadedness; fast or irregular heartbeat; muscle pain; stomach pain with nausea and vomiting; shortness of breath or difficulty breathing; flu-like symptoms such as fever, chills, or cough; or feeling cold, especially in the arms or legs
• light-colored bowel movements; yellowing of the skin or eyes; loss of appetite; unusual bleeding or bruising; dark yellow or brown urine; or pain in the upper right part of stomach

Abacavir may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Store liquid medication at room temperature or in the refrigerator. Do not freeze.

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reach. https://www.upandaway.org

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website https://goo.gl/c4Rm4p for more information.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What OTHER INFORMATION should I know?

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a supply of abacavir on hand. Do not wait until you run out of medication to refill your prescription.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

^¶ This branded product is no longer on the market. Generic alternatives may be available.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™. © Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: August 15, 2025.