Emtricitabine and tenofovir are antiviral medicines that prevent human immunodeficiency virus (HIV) from multiplying in your body.

Emtricitabine and tenofovir is a combination medicine used to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS). This medicine is not a cure for HIV or AIDS, but it can be used to treat HIV in adults and children who are at least 12 years old and weigh at least 17 kilograms (37 pounds).

Emtricitabine and tenofovir is also used in children who weigh between 55 and 77 pounds (25 to 35 kilograms) and who take certain other HIV medications.

Truvada PrEP is used together with safer-sex practices to reduce the risk of becoming infected with HIV. You must be HIV-negative and an adult to use Truvada PrEP for this purpose.

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

You should not take this medicine if you are allergic to emtricitabine or tenofovir. Do not take if you also use other medicines that contain emtricitabine, tenofovir, lamivudine, or adefovir (such as Atripla, Combivir, Complera, Descovy, Dutrebis, Emtriva, Epivir, Epzicom, Genvoya, Hepsera, Odefsey, Stribild, Triumeq, Trizivir, or Viread).

If you take Truvada PrEP to reduce your risk of HIV infection: You must have a negative HIV test immediately before you start taking the medicine.

Do not take Truvada PrEP to reduce infection risk if you are HIV-positive, if have been exposed to HIV within the past month, or if you had any symptoms (such as fever, sore throat, night sweats, swollen glands, diarrhea, body aches).

Tell your doctor if you have ever had:

• liver disease (you may be tested for hepatitis B before you can use this medicine);
• osteopenia (low bone mineral density); or
• kidney disease.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, if you've taken HIV medication for a long time, or if you are a woman. Ask your doctor about your risk.

Tell your doctor if you are pregnant, and use your medications properly to control your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track any effects of antiviral medicine on the baby.

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

A child receiving this medicine must weigh at least 37 pounds.

Use Emtricitabine And Tenofovir (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Mild symptoms of lactic acidosis may worsen over time, and this condition can be fatal. Get emergency medical help if you have: unusual muscle pain, trouble breathing, stomach pain, vomiting, irregular heart rate, dizziness, feeling cold, or feeling very weak or tired.

Call your doctor at once if you have:

• symptoms of new HIV infection--fever, night sweats, tiredness, muscle or joint pain, sore throat, vomiting, diarrhea, rash, swollen glands in your neck or groin;
• sudden or unusual bone pain;
• kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath; or
• liver problems--nausea, swelling around your midsection, upper stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Emtricitabine and tenofovir affects your immune system, which may cause certain side effects (even weeks or months after you've taken this medicine). Tell your doctor if you have:

• signs of a new infection--fever, sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;
• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or
• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Common side effects may include:

• headache, dizziness, feeling depressed or tired;
• trouble sleeping, strange dreams;
• nausea, stomach pain;
• weight loss; or
• rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Using this medicine will not prevent your disease from spreading. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.