Abacavir is an antiviral medication that prevents human immunodeficiency virus (HIV) cells from multiplying in your body.

Abacavir is used to treat HIV, which causes the acquired immunodeficiency syndrome (AIDS). Abacavir is not a cure for HIV or AIDS.

Abacavir may also be used for purposes not listed in this medication guide.

Stop using abacavir and call your doctor at once if you have any of these signs of an allergic reaction: fever; rash; nausea, vomiting, diarrhea, stomach pain; general ill feeling, extreme tiredness, body aches; shortness of breath, cough, sore throat.

Once you have had an allergic reaction to abacavir, you must never use it again.

Read the Warning Card that comes with this medication, and carry it with you at all times so you will know the symptoms of allergic reaction to watch for.

Some people develop lactic acidosis while taking abacavir. Early symptoms may get worse over time and this condition can be fatal. Get emergency medical help if you have even mild symptoms such as: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

Abacavir can also cause severe or life-threatening effects on your liver. Call your doctor at once if you have any of these symptoms while taking abacavir: pain in your upper stomach, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Do not allow this 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 in a row, you may have a dangerous or even fatal allergic reaction once you start taking abacavir again. If you stop taking abacavir for any reason, talk to your doctor before you start taking the medication again.

Do not take this medication if you have ever had an allergic reaction to any medicine that contains abacavir, including Ziagen, Epzicom, or Trizivir. Once you have had an allergic reaction to abacavir, you must never use it again.

Some people develop a life-threatening condition called lactic acidosis while taking abacavir. You may be more likely to develop lactic acidosis if you are overweight or have liver disease, if you are a woman, or if you have taken HIV or AIDS medications for a long time. Talk with your doctor about your individual risk.

Abacavir can also cause severe or life-threatening effects on your liver. You should not take abacavir if you have moderate or severe liver disease.

Do not take abacavir with any other medication that contains abacavir, such as Epzicom or Trizivir.

To make sure you can safely take abacavir, tell your doctor if you have any of these other conditions:

• liver disease;

• heart disease, high blood pressure;

• a risk factor for heart disease such as smoking, diabetes, or high cholesterol; or

• if you have used an HIV medication in the past, such as didanosine (Videx), emtricitabine (Atripla, Complera, Emtriva, Truvada), lamivudine (Combivir, Epivir, Epzicom, Trizivir), stavudine (Zerit), tenofovir (Viread), zalcitabine (Hivid), or zidovudine (Retrovir).

You may need a blood test before you start taking abacavir for the first time, or if you are restarting the medication after stopping for reasons not related to an allergic reaction.

FDA pregnancy category C. It is not known whether abacavir will harm an unborn baby. HIV can be passed to your baby if you are not properly treated during pregnancy. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Take all of your HIV medicines as directed to control your infection.

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of abacavir on the baby.

Women with HIV or AIDS should not breast feed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.