Emtricitabine and tenofovir alafenamide

Pronunciation: em-try-SITE-a-been and ten-NO-foe-vir al-a-FEN-a-mide
Generic name: emtricitabine and tenofovir alafenamide
Brand name: Descovy
Dosage form: oral tablet
Drug class: Antiviral combinations

Medically reviewed by Carmen Pope, BPharm. Last updated on Mar 18, 2025.

What is emtricitabine/tenofovir alafenamide?

Emtricitabine and tenofovir alafenamide is an oral combination antiviral tablet used to treat and prevent HIV-1 infection in adults and adolescents. It is taken once a day. The brand name is Descovy. 

Emtricitabine/tenofovir alafenamide was approved for use as an HIV treatment on April 4, 2016, under the brand Descovy made by Gilead Sciences, Inc.

• Approval was expanded to include PrEP on October 3, 2019.
• There is no generic.

FDA approvals and indications

HIV-1 Treatment:

• Adults and children ≥77 lbs (35 kg): Approved for use with other HIV-1 medicines
• Children 31-77 lbs (14-35 kg): Approved with certain HIV-1 medicines (excluding some protease inhibitors).

HIV-1 PrEP:

• Adults and adolescents ≥77 lbs (35 kg): Approved to reduce HIV-1 infection risk
• Not established for effectiveness in all types of sexual exposure
• Not approved for people born female (assigned female at birth) at risk from vaginal sex due to lack of studies in this population.

Before starting emtricitabine and tenofovir alafenamide for HIV-1 PrEP

You must:

• Confirm you are HIV-negative through testing
• Get tested for hepatitis B (HBV)
• Inform your healthcare provider about any flu-like symptoms within the last month
• Discuss all existing medical conditions and medications.

To use emtricitabine and tenofovir alafenamide safely for HIV prevention:

• Maintain regular HIV testing (at least every 3 months)
• Practice safer sex using latex or polyurethane condoms
• Get regular STI testing
• Never miss doses
• Know your partner's HIV status
• Report any potential HIV exposure immediately.

Side effects

The most common side effects of emtricitabine/tenofovir alafenamide are:

• nausea (most common when used for HIV-1 treatment)
• diarrhea (most common when used for HIV-1 PrEP)
• headache, dizziness, feeling depressed or tired
• sleep problems (insomnia), strange dreams
• stomach pain
• weight loss
• rash.

Serious side effects and warnings

Emtricitabine/tenofovir alafenamide can cause the following serious side effects:

• Worsening of hepatitis B virus (HBV) infection. Your healthcare provider will test you for HBV infection before and when you start treatment with emtricitabine and tenofovir alafenamide
  • HBV may worsen or flare up if you stopthis medicine
  • Regular monitoring is required, and for several months after stopping emtricitabine and tenofovir alafenamide
  • Do not run out of emtricitabine and tenofovir alafenamide and never stop your medication without a healthcare provider consultation.
• Immune System Changes. Changes in your immune system can happen when you start taking medicines to treat HIV-1 infection.
  • Your immune system may become stronger and begin to fight infections that have been hidden in your body for a long time.
  • Watch for signs of new infections.
  • Report any unusual symptoms to your healthcare provider.
• Kidney Problems. New or worse kidney problems, including kidney failure, may develop after starting emtricitabine and tenofovir alafenamide.
  • Regular blood and urine tests are needed.
  • This may require dose adjustments.
• Lactic Acidosis. Rarely, emtricitabine and tenofovir alafenamide may cause too much lactic acid to build up in your blood. Seek immediate medical attention for:
  • unusual muscle pain
  • breathing difficulties
  • severe fatigue
  • stomach pain with nausea
  • irregular heartbeat.
• Liver Problems. Rarely, emtricitabine and tenofovir alafenamide may cause severe liver problems that can lead to death. Watch for:
  • yellowing of skin or eyes
  • dark urine
  • light-colored stools
  • loss of appetite
  • stomach pain.

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

Get emergency medical help if you have signs of an allergic reaction to emtricitabine and tenofovir alafenamide, such as hives, difficulty breathing, or swelling of your face, lips, tongue, or throat.

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 the FDA at 1-800-FDA-1088.

Related/similar drugs

Before taking this medicine

Emtricitabine/tenofovir alafenamide can only help reduce your risk of getting HIV-1 infection before you are infected.

Do not take emtricitabine and tenofovir alafenamide for HIV-1 PrEP if:

• you already have an HIV-1 infection. If you are HIV-1 positive, you need to take other medicines with emtricitabine and tenofovir alafenamide to treat HIV-1. Emtricitabine and tenofovir alafenamide by itself is not a complete treatment for HIV-1
• you do not know your HIV-1 infection status. You may already be HIV-1 positive. You need to take other HIV-1 medicines with emtricitabine and tenofovir alafenamide to treat HIV-1 infection.

Before taking, tell your healthcare provider about all of your medical conditions, including if you:

• have any flu-like symptoms
• have liver problems, including HBV infection
• have kidney problems
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Pregnancy

It is not known if emtricitabine and tenofovir alafenamide can harm your unborn baby. Tell your healthcare provider if you become pregnant during treatment with emtricitabine and tenofovir alafenamide.

Pregnancy Registry: There is a pregnancy registry for people who take emtricitabine and tenofovir alafenamide during pregnancy. The purpose of this registry is to collect information about the health of you and your baby. Talk with your healthcare provider about how you can take part in this registry.

Breastfeeding

Do not breastfeed if you take emtricitabine and tenofovir alafenamide for treatment of HIV-1 because of the risk of passing HIV-1 to your baby.

One of the ingredients in emtricitabine and tenofovir alafenamide (emtricitabine) passes into your breast milk.

How do I take emtricitabine/tenofovir alafenamide?

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

• Take 1 tablet daily
• Take with or without food

For dialysis patients: Take after dialysis

Never skip doses or stop treatment without medical advice

• Maintain an adequate supply. Do not run out of emtricitabine and tenofovir alafenamide as it may increase your risk of infection from HIV and other viruses.
• You must also use safer sex practices and get tested for HIV before starting prophylaxis and at least once every 3 months.

What happens if I miss a dose?

Take the medicine as soon as you remember, and then go back to your regular schedule. Do not use two doses at one time.

• Skipping doses could make the virus resistant to medication or increase your risk of becoming infected with HIV.
• Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

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

What other drugs will affect emtricitabine and tenofovir alafenamide?

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

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

Tell your doctor about all your other medicines, especially:

• seizure medicine - carbamazepine, oxcarbazepine, phenytoin, phenobarbital; or

• other antiviral medicine to treat hepatitis C or HIV.

This list is not complete and many other drugs may interact with emtricitabine and tenofovir. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Emtricitabine and tenofovir alafenamide ingredients

Active ingredient: emtricitabine and tenofovir alafenamide.
Inactive ingredients: croscarmellose sodium, magnesium stearate, and microcrystalline cellulose.

The 200 mg/25 mg tablets are film-coated with a coating material containing indigo carmine aluminum lake, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

The 120 mg/15 mg tablets are film-coated with a coating material containing polyvinyl alcohol, titanium dioxide, polyethylene glycol, and talc.

Available as

• Descovy 120 mg/15 mg (emtricitabine 120 mg and tenofovir alafenamide 15 mg)
• Descovy 200 mg/25 mg (emtricitabine 200 mg and tenofovir alafenamide 25 mg).

Storage

• Store your emtricitabine and tenofovir alafenamide tablets at room temperature (68°F to 77°F)
• Keep them in their original container.

Who makes emtricitabine and tenofovir alafenamide?

Emtricitabine and tenofovir alafenamide (brand name Descovy) is manufactured by Gilead Sciences, Inc., a biopharmaceutical company based in Foster City, California.

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