Epzicom is a two-in-one combination pill containing Epivir (lamivudine or 3TC) and Ziagen (abacavir). Putting more than one drug in a single tablet means you can take fewer pills each day and may have lower insurance co-payments.

Epzicom 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 Epzicom for use in combination with other HIV drugs for the treatment of HIV infection in adults over age 18. Epzicom has not been tested in children.

Epzicom comes as a tablet that contains:

• 300 milligrams (mg) of Epivir
• 600 mg of Ziagen

The usual dose is one tablet daily.

Epzicom must be used with other medications to treat HIV from the protease inhibitor or non-nucleoside reverse transcriptase inhibitor (NNRTI) drug classes. It should not be used only with other NRTIs.

You can take Epzicom with food or on an empty stomach, but taking it with food may cut down on nausea or other side effects.

You should not take Epzicom if you have experienced a hypersensitivity reaction to Ziagen.

Speak to your doctor if you weigh less than 110 pounds (50 kg) or if you have liver or kidney problems.

As with all HIV drugs, it is important to take Epzicom 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.

Epzicom can be used if you’re just starting HIV treatment.

Epzicom can be used if you’ve been on treatment before, but it is not clear if Epzicom will work for people who are already resistant to Epivir or Ziagen.

Your doctor can run a resistance test to help determine whether the drugs in Epzicom are likely to work for you.

The Ziagen in Epzicom 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 Epzicom, then it may stop working or not work as well for you. You also may not get as much benefit from other NRTIs.

Sometimes taking more than one medication can cause drug interactions. Taking certain drugs (including methadone) with Epzicom can change the amount of each drug in your blood. Your doctor may need to adjust the doses of your drugs to avoid under- or overdosing.

Some drugs should not be taken with Epzicom, including Epivir, Ziagen, Emtriva, Combivir, Trizivir, and Truvada.

You should also avoid using alcohol while taking Epzicom.

Several other medications may make the side effects of Epzicom worse. 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.

Epzicom is associated with the same side effects as the drugs it contains. 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.

• Nausea
• Diarrhea
• Loss of appetite
• Headaches
• Dizziness
• Fatigue (unusual tiredness)
• Insomnia (trouble falling or staying asleep)
• Depression
• Rash

More serious side effects:

• Hypersensitivity reaction: About 5-10 percent of people who take Ziagen—which is included in Epzicom—develop a very serious, potentially fatal side effect called a hypersensitivity reaction. Signs to watch for include fever, skin rash, severe nausea, vomiting, or abdominal pain; and cough, sore throat, or difficulty breathing. If you experience any of these symptoms, call your doctor immediately. If your doctor has you stop taking Epzicom because of a suspected hypersensitivity reaction, do not take Epzicom, Ziagen, or Trizivir ever again. All fatal hypersensitivity reactions have happened when someone re-started the drug after discontinuation.
• Low white blood cell count (neutropenia) or low red blood cell count ( anemia).
• An increase of lactic acid in the blood ( lactic acidosis), an enlarged 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; and 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 Epzicom 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.

There have been no clinical studies on the Epzicom combination pill. The drugs in Epzicom (Epivir and Ziagen) have been studied in both men and women (see the fact sheets on these separate drugs for more information). Their effectiveness and side effects seem very similar in both men and women. One study of 67 women and 304 men showed that the pharmacokinetics of Ziagen (how the drug is processed by the body) are similar in women and men. 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.

Study CNA30024 showed that Epivir plus Ziagen plus Sustiva (efavirenz) controlled HIV as well as Retrovir (zidovudine or AZT) plus Epivir plus Sustiva, but the Ziagen regimen led to greater CD4 cell increases. This study included 649 participants, of whom 19 percent (about 123) were women. Study CNA30021 (also called ZODIAC) showed that 600 mg of Ziagen once daily (the dose in the Epzicom pill) plus Epivir and Sustiva worked as well as 300 mg of Ziagen twice daily plus the same two drugs. However, hypersensitivity reactions were slightly more common when people took the higher once-daily dose of Ziagen. This study included 770 participants, of whom 19 percent (or about 146) were women. Study CNA10905 showed that Ziagen lasts a long time in the body, which means it is safe to use the drug just once daily. This study included eight women and 12 men.

Studies have shown that pregnant women who use HIV drugs can greatly reduce the risk of passing HIV on to their babies. Epivir has 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 Ziagen or the Epzicom combination pill 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 Epzicom, is used to treat hepatitis B (HBV) infection. If you are co-infected with HIV and HBV and taking Epzicom for HIV treatment, discontinuing the drug may result in a worsening of hepatitis. If you are co-infected, speak to your doctor about treatment options.

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.