by Liz Highleyman
January 2004 (Reviewed and Revised November 2006)
Combivir is a two-in-one combination pill containing Retrovir (zidovudine or AZT) and Epivir (lamivudine or 3TC). Putting more than one drug in a single tablet means you get to take fewer pills each day and may have lower insurance co-payments.
Combivir is made up of HIV drugs from a class called nucleoside reverse transcriptase inhibitors (NRTIs), also known as nucleoside analogs or “nukes.”
The NRTIs block reverse transcriptase, a protein that HIV needs to make more copies of itself. This may slow down HIV disease.
The Food and Drug Administration (FDA) has approved Combivir for use in combination with other HIV drugs for the treatment of HIV infection in adults and adolescents over 12 years of age.
The FDA also granted tentative approval of a generic formulation of Combivir, although this version is not yet available in the U.S.
Combivir comes as a tablet that contains:
- 300 milligrams (mg) of Retrovir
- 150 mg of Epivir
The dose is one tablet twice daily.
Combivir must be used with other HIV medications to treat HIV.
You can take Combivir with food or on an empty stomach, but taking it with food may cut down on nausea or other side effects.
Speak to your doctor if you have liver, kidney, or pancreas problems or anemia.
As with all HIV drugs, it is important to take Combivir as prescribed. Missing or skipping doses can cause your blood levels of the drug to fall too low and resistance can develop. When your virus becomes resistant to an HIV medication, that drug may stop working.
Combivir can be used if you’re just starting on treatment.
Combivir can be used if you’ve been on treatment before. In fact, the Retrovir in Combivir may work better if you have Epivir-resistant virus.
Your doctor can run a resistance test to help determine whether the drugs in Combivir are likely to work for you.
The Retrovir in Combivir crosses the blood-brain barrier (which protects the brain and spinal cord), so it may be able to fight HIV in the brain.
If your virus develops resistance to the drugs in Combivir then it may stop working or not work as well for you. You also may not get as much benefit from some of the other NRTIs.
Sometimes taking more than one medication can cause drug interactions. Taking certain drugs with Combivir can change the amount of each drug in your blood (including methadone and ribavirin). Your doctor may need to adjust the doses of your drugs to avoid under- or overdosing.
Some drugs should not be taken with Combivir, such as Trizivir, Retrovir, Epivir, Zerit (stavudine or d4T), Emtriva (emtricitabine or FTC), Epzicom, Truvada, and Hivid (zalcitabine or ddC). You should also avoid using alcohol while taking Combivir.
Several other medications can make the side effects of Combivir worse (including interferon). Be sure your doctor knows about all the medications you are taking (including over-the-counter, prescription, street drugs, and herbs), even if you only use them occasionally.
For more information and additional resources to check interactions between the particular drugs you are taking, see our info sheet on drug interactions.
Combivir is associated with the same side effects as the drugs it contains. However, the side effects are likely to be temporary and go away as your body adjusts to the medication. If you are experiencing any of the side effects listed below, call your doctor for advice. Do not just stop taking your medication.
- Loss of appetite
- Fatigue (unusual tiredness)
- Insomnia (trouble falling or staying asleep)
More serious side effects:
- Low white blood cell count (neutropenia) or low red blood cell count ( anemia)
- Myopathy (muscle damage) – this can make your muscles feel achy and weak
- An increase of lactic acid in the blood ( lactic acidosis), an enlarged and fatty liver, and liver failure have been reported in people using NRTIs. Lactic acidosis is a rare but potentially fatal side effect. Symptoms include nausea, vomiting, or stomach pain; feeling very weak and tired; shortness of breath.
- Lipodystrophy, which may include elevated blood sugar (glucose), elevated lipid levels ( cholesterol and triglycerides), and fat gain or loss in certain areas. The exact causes of lipodystrophy are not known, but may include HIV and/or HIV drugs. It is unclear if the drugs in Combivir will cause or impact symptoms of lipodystrophy. For more information on lipodystrophy, see our info sheet.
If you are experiencing persistent, unusual, or serious side effects, call your doctor right away.
Combivir has been studied in both men and women. Its effectiveness and side effects seem very similar in both men and women. But some research suggests that women are more likely than men to develop liver problems and the rare, but very serious side effect, lactic acidosis, while taking NRTI drugs.
The drugs in the combination Combivir pill— Retrovir and Epivir—have been studied in many women (see the info sheets on these separate drugs for more information).
Retrovir greatly reduces transmission of HIV from mother to child. Retrovir and Epivir have been used during pregnancy without any significant negative effect to mother or baby; however, long- term effects on the child are not known.
There have been no formal studies on the use of Combivir during pregnancy. Check with your doctor about the best treatment options for you and your baby if you are thinking of getting pregnant.
Click this link for more information about pregnancy.
A lower dose formulation of Epivir, one of the components of Combivir, is used to treat hepatitis B (HBV) infection. Get tested for hepatitis B before you start taking Combivir to treat HIV.
If you are co-infected with HIV and HBV, speak to your doctor about treatment options. In addition, if you are co-infected and taking Combivir for HIV treatment, discontinuing the drug may result in worsening hepatitis symptoms.
People who are starting HIV treatment for the first time may develop Immune Reconstitution Syndrome or IRS (also called Immune Reconstitution Inflammatory Syndrome or IRIS). IRS can happen as a result of the immune system getting stronger and responding to an HIV-related infection such as Mycobacterium avium infection (MAC), cytomegalovirus (CMV), Pneumocystis jirovecii pneumonia (PCP), or tuberculosis (TB). People may have been treated for these infections in the past or not even know they have them. If you notice any unusual symptoms soon after starting HIV drugs for the first time, let your doctor know right away so you can be evaluated and, if necessary, treated.
National Institute of Allergy and Infectious Diseases. (2003). Clinical advisory: important interim results from a phase III, randomized, double-blind comparison of three protease-inhibitor-sparing regimens for the initial treatment of HIV infection ( AACTG Protocol A5095).
Opravil, M., et. al. (2002). A randomized trial of simplified maintenance therapy with abacavir, lamivudine, and zidovudine in human immunodeficiency virus infection. Journal of Infectious Diseases, 185(9). 1251-1260.
Podzamczer, D., et. al. (2000). A randomized, open, multicenter trial comparing Combivir plus nelfinavir or nevirapine in HIV-infected naïve patients (the COMBINE study). 40th Interscience Conference on Antimicrobial Agents and Chemotherapy. Toronto, Canada. Abstract 694.