Emtricitabine and tenofovir are antiviral drugs that work by preventing HIV (human immunodeficiency virus) cells from multiplying in the body.

The combination of emtricitabine and tenofovir is used to treat HIV, which causes acquired immunodeficiency syndrome (AIDS). Emtricitabine and tenofovir is not a cure for HIV or AIDS.

Emtricitabine and tenofovir may also be used for other purposes not listed in this medication guide.

You should not take this medication if you are allergic to emtricitabine (Emtriva) or tenofovir (Viread).

Do not take this medication with other medicines that also contain emtricitabine or tenofovir (Atripla, Emtriva, Viread), or lamivudine (Combivir, Epivir, Epzicom, or Trizivir).

Some people develop lactic acidosis while taking emtricitabine and tenofovir. 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.

Emtricitabine and tenofovir can cause severe or fatal liver problems. Call your doctor at once if you have symptoms such as nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

You should not take this medication if you are allergic to emtricitabine (Emtriva) or tenofovir (Viread). Do not take this medication with other medicines that also contain emtricitabine or tenofovir (Atripla, Emtriva, Viread), or lamivudine (Combivir, Epivir, Epzicom, or Trizivir).

If you have any of these other conditions, you may need an emtricitabine and tenofovir dose adjustment or special tests:

• liver or kidney disease;

• osteopenia (low bone mineral density); or

• if you also have hepatitis B infection.

Some people develop a life-threatening condition called lactic acidosis while taking emtricitabine and tenofovir. 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.

FDA pregnancy category B. Emtricitabine and tenofovir is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

HIV can be passed to your baby if you are not properly treated during pregnancy. 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 emtricitabine and tenofovir 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.

Do not give this medicine to anyone under 18 without the advice of a doctor.