Descovy (emtricitabine and tenofovir) is an antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body.

Descovy is approved for use for HIV-1 pre-exposure prophylaxis (PrEP) to reduce the risk of HIV-1 infection from sex, excluding those who have receptive vaginal sex.

Descovy is also approved 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).

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

Descovy 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 this medicine for this purpose.

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

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 Descovy. You may need frequent liver function tests for several months.

Take Descovy exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

You may take Descovy 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.

Store Descovy 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 Descovy 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, Dutrebis, Emtriva, Epivir, Epzicom, Genvoya, Hepsera, Odefsey, Stribild, Triumeq, Trizivir, or Viread).

To make sure Descovy is safe for you, 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.

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.

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.

Get emergency medical help if you have signs of an allergic reaction to Descovy: 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.

Descovy 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 affect 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 Descovy 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.

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.

Descovy 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 interact with 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.