Name: Abacavir

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Do not allow your medicine to run out completely before you get your prescription refilled. It is important that you not stop taking abacavir once you have started. If you miss several doses, you may have a dangerous or even fatal allergic reaction once you start taking abacavir again.


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Pharmacologic Category

  • Antiretroviral, Reverse Transcriptase Inhibitor, Nucleoside (Anti-HIV)

Use Labeled Indications

HIV-1 infection: Treatment of HIV-1 infection in combination with other antiretroviral agents

Do I need a prescription for abacavir?


Is abacavir safe to take if I'm pregnant or breastfeeding?

Use of abacavir during pregnancy has not been adequately evaluated.

It is not known whether abacavir is excreted in breast milk. HIV infected mothers should not breast feed because of the potential risk of transmitting HIV to an infant that is not infected.

Abacavir Overview

Abacavir is a prescription medication used to treat human immunodeficiency virus (HIV) infection. Abacavir belongs to a group of drugs called nucleoside analogue reverse transcriptase inhibitors (NRTIs). It works by preventing the virus from multiplying.

This medication comes in tablet and liquid forms and is usually taken once or twice daily.

Common side effects of abacavir include nausea, vomiting, tiredness, and headaches.

Abacavir Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of abacavir, there are no specific foods that you must exclude from your diet when receiving abacavir.

Abacavir and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

This medication falls into category C. In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.

If you take this medication while you are pregnant, talk to your healthcare provider about how you can take part in the Pregnancy Registry. The purpose of the pregnancy registry is to collect information about the health of you and your baby.

Abacavir FDA Warning


Serious and sometimes fatal hypersensitivity reactions have been associated with abacavir sulfate.

Hypersensitivity to abacavir is a multi-organ clinical syndrome usually characterized by a sign or symptom in 2 or more of the following groups: (1) fever, (2) rash, (3) gastrointestinal (including nausea, vomiting, diarrhea, or abdominal pain), (4) constitutional (including generalized malaise, fatigue, or achiness), and (5) respiratory (including dyspnea, cough, or pharyngitis). Discontinue abacavir as soon as a hypersensitivity reaction is suspected.

Patients who carry the HLA-B*5701 allele are at high risk for experiencing a hypersensitivity reaction to abacavir sulfate. Prior to initiating therapy with abacavir, screening for the HLA-B*5701 allele is recommended; this approach has been found to decrease the risk of hypersensitivity reaction. Screening is also recommended prior to reinitiation of abacavir in patients of unknown HLA-B*5701 status who have previously tolerated abacavir. HLA-B*5701-negative patients may develop a suspected hypersensitivity reaction to abacavir; however, this occurs significantly less frequently than in HLA-B*5701-positive patients.

Regardless of HLA-B*5701 status, permanently discontinue abacavir sulfate if hypersensitivity cannot be ruled out, even when other diagnoses are possible.

Following a hypersensitivity reaction to abacavir sulfate, NEVER restart abacavir sulfate or any other abacavir-containing product because more severe symptoms can occur within hours and may include life-threatening hypotension and death.

Reintroduction of abacavir sulfate or any other abacavir-containing product, even in patients who have no identified history or unrecognized symptoms of hypersensitivity to abacavir sulfate therapy, can result in serious or fatal hypersensitivity reactions. Such reactions can occur within hours.

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination, including abacavir sulfate and other antiretrovirals.

Liver Dose Adjustments

Mild liver dysfunction (Child-Pugh A): 200 mg orally twice a day
Moderate or severe liver dysfunction: Contraindicated


-HYPERSENSITIVITY REACTIONS: Serious and sometimes fatal hypersensitivity reactions (with multiple organ involvement) reported with this drug. Patients with the human leukocyte antigen subtype B*5701 (HLA-B*5701) allele are at higher risk of abacavir hypersensitivity reactions; however, such reactions have occurred in patients without the HLA-B*5701 allele. This drug is contraindicated in patients with prior hypersensitivity reaction to abacavir and in HLA-B*5701-positive patients. All patients should be screened for the HLA-B*5701 allele before starting or restarting treatment with this drug (unless HLA-B*5701 allele assessment previously documented). Regardless of HLA-B*5701 status, this drug should be discontinued without delay if hypersensitivity reaction is suspected, even if other diagnoses are possible. After hypersensitivity reaction to this drug, NEVER restart this or any other abacavir-containing product as more severe symptoms (including death) can occur within hours. Similar severe reactions also reported after restarting abacavir-containing products in patients with no history of abacavir hypersensitivity.
-LACTIC ACIDOSIS AND SEVERE HEPATOMEGALY WITH STEATOSIS: Lactic acidosis and severe hepatomegaly with steatosis (including fatalities) reported with use of nucleoside analogs and other antiretrovirals. This drug should be discontinued if clinical or laboratory findings suggest lactic acidosis or pronounced hepatotoxicity.

Safety and efficacy have not been established in patients younger than 3 months.

Consult WARNINGS section for additional precautions.