Ziagen (Abacavir) for HIV

Ziagen (abacavir) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to treat human immunodeficiency virus type 1 (HIV-1) in adults and children aged 3 months and older.

How Ziagen Works and How It’s Taken

Ziagen is a type of antiretroviral medicine used with other HIV medicines to treat HIV-1 infection.

Abacavir works by blocking an HIV-1 enzyme called reverse transcriptase. The virus needs this enzyme to make copies of itself. When Ziagen is used with other HIV medicines, it may lower the amount of HIV-1 in the blood. This is called the viral load. It may also increase the number of CD4-positive T cells, which help the body fight infections.

Lowering the amount of HIV-1 and increasing CD4-positive T cells may help the immune system work better. This may lower the risk of death or infections that can happen when the immune system is weak.

HIV-1 is the virus that causes acquired immune deficiency syndrome (AIDS).

Ziagen comes as a tablet and an oral solution. It is taken by mouth once or twice daily, depending on the prescribed dose. It may be taken with or without food.

Typical Dosing for HIV

For adults, the recommended dose of Ziagen is 600 milligrams each day. It may be taken as 300 milligrams twice daily or 600 milligrams once daily. Ziagen is used with other antiretroviral medicines.

For children aged 3 months and older, the dose is based on body weight. The oral solution may be given as 8 milligrams per kilogram twice daily or 16 milligrams per kilogram once daily. The total dose should not be more than 600 milligrams each day.

For children who weigh at least 14 kilograms and can swallow scored tablets:

14 to less than 20 kilograms — 300 milligrams once daily or 150 milligrams twice daily
20 to less than 25 kilograms — 450 milligrams once daily or 150 milligrams in the morning and 300 milligrams in the evening
25 kilograms or more — 600 milligrams once daily or 300 milligrams twice daily

For people with mild liver impairment, called Child-Pugh Class A, the recommended dose is 200 milligrams twice daily. The oral solution should be used at a dose of 10 milliliters twice daily. Ziagen should not be used in people with moderate or severe liver impairment.

This information is based on prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Ziagen Side Effects

Nausea
Headache
Malaise (generally not feeling well)
Fatigue (tiredness)
Vomiting
Bad dreams or sleep problems

The most common side effects in children include:

Fever
Chills
Rash
Ear, nose, or throat infections
Nausea
Vomiting

Serious Side Effects and Warnings

Ziagen can cause serious side effects that may require immediate medical attention. These include:

Serious allergic reaction — Hypersensitivity reactions can involve multiple organs and may be life-threatening; these often include fever and/or rash and may also include stomach symptoms, extreme tiredness or achiness, or breathing symptoms.
Lactic acidosis and severe liver problems — A dangerous buildup of lactic acid in the blood and an enlarged, fatty liver can be fatal.
Immune reconstitution syndrome — Changes in the immune system after starting HIV treatment can trigger inflammation related to past infections; autoimmune conditions have also been reported.
Heart attack — Myocardial infarction, a heart-related emergency, has been reported; the overall evidence for a direct cause is inconclusive.

Get medical help right away if you think you are having a serious reaction.

How To Save on Ziagen

ViiV Healthcare, the manufacturer of Ziagen, offers the ViiVConnect Copay Program. Eligible people may pay as little as $0 per prescription fill.

The program also offers reimbursement if your pharmacy can’t process the savings card.

To learn more, visit the ViiVConnect Copay Program website or call 866-279-4705.

What To Know Before Taking Ziagen

Before starting Ziagen, your doctor should test you for a gene variation called HLA-B*5701.

Tell your doctor if you have any allergies to abacavir or any ingredients in Ziagen.

Before taking Ziagen, tell your doctor if you:

Have been tested for the HLA-B*5701 gene variation
Have or have had liver problems, including hepatitis B or C
Have heart problems, smoke, or have conditions that raise your risk of heart disease, such as high blood pressure, high cholesterol, or diabetes
Drink alcohol or take medicines that contain alcohol

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.

Do not take Ziagen if you:

Have the HLA-B*5701 allele
Have ever had a serious allergic reaction, also called a hypersensitivity reaction, to abacavir
Have moderate or severe liver impairment

Do not let your supply of Ziagen run out. If you stop taking it, the amount of HIV-1 in your blood may increase and the virus may become harder to treat.

If you miss a dose of Ziagen, take it as soon as you remember. Do not take two doses at the same time or take more than your prescribed dose.

If you are pregnant or plan to become pregnant, talk with your doctor.

A pregnancy registry tracks pregnancy outcomes in people exposed to Ziagen. Healthcare providers can register pregnancies by visiting the Antiretroviral Pregnancy Registry or calling 800-258-4263.

Do not breastfeed while taking Ziagen.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Ziagen for HIV?

Ziagen has been studied as part of combination HIV treatment. In one 48-week study of adults who had not been treated for HIV-1 before, 69 percent of people taking Ziagen with lamivudine and efavirenz had a treatment response. This was the same response rate seen with zidovudine, lamivudine, and efavirenz.

In another 48-week adult study, 49 percent of people taking Ziagen with lamivudine/zidovudine had a treatment response, compared with 50 percent taking indinavir with lamivudine/zidovudine.

In one 16-week study in children, 13 percent of those taking Ziagen with lamivudine and zidovudine had an HIV-1 viral load of 400 copies per milliliter or less. This compared with 2 percent of children taking lamivudine and zidovudine without Ziagen.

How long does Ziagen take to work for HIV?

The study does not say exactly how many days or weeks it takes for Ziagen to start working. Clinical studies measured treatment results at 16 weeks in one pediatric study and at 48 weeks in adult studies. These were study measurement points, not the exact time when Ziagen begins to work.

When used with other HIV medicines, Ziagen may help lower the amount of HIV-1 in the blood and increase CD4-positive T cells, which help the body fight infections.

What tests or monitoring are needed with Ziagen for HIV?

Before starting or restarting Ziagen, your doctor should test you for a gene variation called HLA-B*5701, unless you already have a documented test result. People with this gene variation have a higher risk of a serious allergic reaction to abacavir.

While taking Ziagen, your doctor will watch for signs of serious allergic reactions and other problems, including liver problems, lactic acidosis, and new symptoms of infection after HIV treatment begins. Heart disease risk factors should also be considered.