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). emtricitabine and tenofovir 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.

Do not take this combination medicine if you also take other medicines that contain emtricitabine, tenofovir, lamivudine, or adefovir.

Truvada PrEP is used to reduce the risk of becoming infected with HIV in adults who are HIV-negative. emtricitabine and tenofovir alone will not protect you from infection with HIV. You must also use safer sex practices and get tested for HIV at least every 3 months.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. Call your doctor or get emergency medical help if you have unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or feeling very weak or tired.

If you've ever had hepatitis B, it may become active or get worse after you stop using emtricitabine and tenofovir. You may need frequent liver function tests for several months.

The combination of emtricitabine and tenofovir comes as a tablet to take by mouth. It is usually taken, with or without food, once a day. Take emtricitabine and tenofovir at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take emtricitabine and tenofovir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are taking emtricitabine and tenofovir (Truvada), your doctor may prescribe or recommend a calcium and vitamin D supplement to take during your treatment. You should take these supplements as directed by your doctor.

If your child is taking emtricitabine and tenofovir (Truvada), swallow the tablet whole. Tell your doctor if your child is unable to swallow the tablets.

Continue to take emtricitabine and tenofovir even if you feel well. Do not stop taking emtricitabine and tenofovir without talking to your doctor.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take emtricitabine and tenofovir with or without food.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

You will need frequent medical tests to check your kidney and liver function, or your bone mineral density.

Truvada PrEP alone will not protect you from infection with HIV. You must also use safer sex practices and get tested for HIV at least every 3 months.

Store in the original container at room temperature, away from moisture and heat. Keep the bottle tightly closed when not in use.

If you've ever had hepatitis B, this virus may become active or get worse in the months after you stop using emtricitabine and tenofovir. You may need frequent liver function tests while using this medicine and for several months after your last dose.

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.

Take the missed dose as soon as you remember. Skipping doses may increase the risk of your virus becoming resistant to antiviral medicine. Try not to miss any doses.

Get your prescription refilled before you run out of medicine completely.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

Using emtricitabine and tenofovir 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.

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.

Emtricitabine and tenofovir may cause serious side effects. 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 of emtricitabine and tenofovir 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.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Emtricitabine and tenofovir can harm your kidneys, especially if you also use certain medicines for infections, cancer, osteoporosis, organ transplant rejection, bowel disorders, high blood pressure, or pain or arthritis (including Advil, Motrin, and Aleve).

Other drugs may affect emtricitabine and tenofovir, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a supply of emtricitabine and tenofovir on hand. Do not wait until you run out of medication to refill your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Descovy® (containing Emtricitabine, Tenofovir)
• Truvada® (containing Emtricitabine, Tenofovir)