Abacavir/lamivudine/zidovudine: HIV treatment, dosing, side effects
Last updated September 6, 2026.
**Abacavir, lamivudine, and zidovudine combine three nucleoside reverse transcriptase inhibitors (NRTIs) in one prescription tablet to treat HIV.** They block an enzyme HIV needs to copy itself, lowering the amount of virus in your blood. Abacavir can cause a serious allergic reaction: you need HLA-B*5701 genetic screening before treatment, and you must never take abacavir again after a suspected reaction unless your clinician rules it out.
What does it treat?
This combination, known as Trizivir, treats HIV type 1 infection, including when you have no symptoms. It helps protect your immune system but does not cure HIV. Your HIV clinician uses your treatment history, resistance testing, and blood tests to decide whether these three medicines fit your regimen.
How do you take it?
Each oral tablet contains 300 mg abacavir, 150 mg lamivudine, and 300 mg zidovudine. The labeled adult dose is one tablet twice daily, with or without food; do not exceed two tablets daily. Take a missed dose when you remember unless it is almost time for the next dose; then skip it without doubling. Stop and contact your clinician immediately for suspected allergy. After a treatment interruption, ask your prescriber before restarting.
Side effects to know
- Common: You may have nausea, vomiting, headache, or tiredness.
- Serious: Stop taking it and get immediate help for suspected allergy, especially symptoms from two groups: fever; rash; nausea, vomiting, diarrhea, or stomach pain; marked tiredness or aches; cough, sore throat, or breathlessness. Severe weakness, unusual muscle pain, yellow skin or eyes, or rapid breathing need urgent assessment for anemia, muscle injury, liver damage, or lactic acid buildup.
Who should not take it?
Do not take it with a positive HLA-B*5701 result or a previous allergy to its ingredients. Liver impairment can prevent use, and kidney impairment may require separate medicines with adjusted doses. Discuss low blood counts, hepatitis B or C, heart disease, pregnancy, and all medicines before treatment. Labeling advises against breastfeeding. Ask before drinking alcohol because it raises abacavir exposure. Do not add medicines containing the same ingredients or emtricitabine.
When is it an emergency?
For overdose, call Poison Control at 1-800-222-1222 immediately, even without symptoms; vomiting, headache, or unusual tiredness may occur. Call 911 for collapse, breathing trouble, or swelling of your tongue or throat. Severe weakness with rapid breathing or persistent vomiting needs emergency evaluation. If you have hepatitis B, stopping treatment can cause a liver flare, so arrange monitoring with your clinician.
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Common questions
What is the maximum daily dose?
Take one tablet twice daily. Do not exceed two tablets in a day. That provides 600 mg abacavir, 300 mg lamivudine, and 600 mg zidovudine.
Can I drink alcohol?
Alcohol increases abacavir exposure. Ask your prescriber before drinking. If you have liver disease, discuss both alcohol and whether this combination is appropriate.
Can I take it during pregnancy or breastfeed?
Tell your HIV clinician promptly if you are pregnant or planning pregnancy. Do not interrupt treatment on your own; your clinician will review the regimen and discuss the pregnancy exposure registry. Labeling advises against breastfeeding because of HIV transmission and potential medicine effects on your baby.
Do I need to take it with food?
You can take it with or without food. Keep consistent morning and evening dosing times. A meal or snack may help with nausea.
What are overdose signs?
Vomiting, headache, or unusual tiredness may occur. Symptoms cannot reliably tell you whether an overdose is dangerous. Call Poison Control at 1-800-222-1222 without waiting for symptoms, and call 911 for collapse or breathing trouble.
Which medicines interact with it?
Avoid duplicate abacavir, lamivudine, or zidovudine and medicines containing emtricitabine. Ribavirin, stavudine, and doxorubicin are combinations your clinician should avoid. Ganciclovir and other medicines that suppress blood cell production can increase toxicity. Methadone may need adjustment by its prescriber.