Combivir combines two antiretroviral medicines, lamivudine and zidovudine, into a single tablet. Both belong to a class called nucleoside reverse transcriptase inhibitors (NRTIs). They are used together as part of combination antiretroviral therapy (ART) to treat HIV-1 infection.

How it works:

HIV uses an enzyme called reverse transcriptase to copy its genetic material inside your cells. Lamivudine and zidovudine both block this enzyme in different ways, making it harder for HIV to replicate. Using two NRTIs together provides a stronger backbone for an antiretroviral regimen.

Combivir does not cure HIV. It keeps the virus suppressed so your immune system remains healthy. Combivir is usually prescribed alongside a third antiretroviral medicine (such as an integrase inhibitor or a protease inhibitor) as part of a complete HIV treatment regimen.

Your dose:

One tablet taken twice daily, approximately 12 hours apart. Always take it exactly as prescribed by your doctor.

How to take it:

• Take Combivir at the same times each day to maintain consistent levels of medicine in your blood
• It can be taken with or without food
• Swallow the tablet whole
  

Before you start:

• Tell your doctor about all medicines, vitamins, and supplements you take
• Let your doctor know if you have any history of kidney, liver, or bone marrow problems
• Tell your doctor if you are pregnant or planning to become pregnant. HIV treatment is important during pregnancy to protect both your health and your baby's. Your doctor will guide you on the safest option

Ongoing check-ups:

Regular blood tests to monitor your viral load, CD4 count, blood counts (as zidovudine can affect the bone marrow), kidney function, and liver health are essential.

• Take the missed dose as soon as you remember
• If it is nearly time for your next dose, skip the missed one and continue your regular schedule
• Never take two doses at once

Consistency is important with HIV treatment. Missing doses can allow the virus to replicate and may lead to resistance. Speak to your doctor or pharmacist if you need help staying on track.

If you think you have taken more than prescribed, call 000 or go to your nearest emergency department straight away. Bring your medicine packet with you.

• Store below 30°C
• Keep in the original packaging, away from moisture and light
• Keep out of reach of children and pets

Side effects can occur, particularly in the early weeks of treatment.

• Nausea, vomiting, and headache: Common at the start. Usually improve after the first few weeks
• Fatigue and malaise: Feeling generally unwell or tired is common initially
• Anaemia and neutropenia: Zidovudine can reduce red and white blood cell production. Regular blood tests monitor for this
• Muscle pain and weakness: Some people develop myopathy (muscle problems) during long-term zidovudine use
• Lactic acidosis: A rare but serious buildup of lactic acid in the blood, which can be life-threatening. Seek immediate help if you develop unusual muscle pain, difficulty breathing, stomach pain, or vomiting
• Liver problems: Including liver enlargement with fat accumulation (hepatic steatosis). Your liver function will be monitored

Contact your doctor or pharmacist if any side effect concerns you.

Tell your doctor and pharmacist everything you are taking. Key interactions include:

• Other antiretrovirals: Your doctor will carefully select medicines that work well together. Some combinations must be avoided
• Medicines that affect bone marrow: Combining zidovudine with other medicines that suppress bone marrow (such as ganciclovir) increases the risk of anaemia and low white cell counts
• Ribavirin: Used for hepatitis C, ribavirin can reduce the effectiveness of zidovudine and increase the risk of anaemia
• Methadone: Can increase zidovudine levels in the blood. Monitoring may be needed

Never start, stop, or change any medicine without speaking to your doctor first.

Is Combivir a complete HIV treatment on its own?

No. Combivir provides two of the medicines needed in an HIV regimen, but it must be taken alongside a third antiretroviral medicine (such as an integrase inhibitor like dolutegravir). Your doctor will prescribe the complete regimen that is right for you.

Why do I take it twice a day when some HIV medicines are once daily?

Zidovudine (one of the two medicines in Combivir) has a shorter duration of action and needs to be taken twice daily. Newer antiretroviral medicines have longer half-lives that allow once-daily dosing. If this is a concern for you, discuss with your doctor whether a regimen with a simpler dosing schedule might be an option.

Ace provides accurate and independent information medically reviewed on prescription medications. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment.