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Generic name: tenofovir alafenamide (ten OF oh vir)
Brand name: Vemlidy
Drug class: Nucleoside reverse transcriptase inhibitors (NRTIs)

Medically reviewed by Philip Thornton, DipPharm. Last updated on Apr 1, 2021.

What is Vemlidy?

Vemlidy (tenofovir alafenamide) is a prescription antiviral medicine that prevents the hepatitis B virus from multiplying in your body.

Vemlidy is used to treat patients with chronic hepatitis B infection in adults with compensated liver disease.

Vemlidy may lower the amount of HBV in your body and may improve the condition of your liver.

It is not known if Vemlidy is safe and effective in children under 18 years of age.


If you have hepatitis B, it may become active or get worse after you stop using Vemlidy. You may need frequent liver function tests for several months.

Do not stop using Vemlidy without first talking to your doctor. If you have ever had hepatitis B, stopping treatment with tenofovir can cause acute exacerbations of hepatitis B. You will need frequent blood tests to check your liver function.

Do not take tenofovir alafenamide together with adefovir (Hepsera), or with combination medicines that contain tenofovir (Atripla, Biktarvy, Cimduo, Complera, Descovy, Genvoya, Odefsey, Stribild, Symfi, or Truvada).

Vemlidy is not recommended in patients with end stage renal disease.

Tenofovir alafenamide (Vemlidy) is used to treat patients with chronic hepatitis B. Tenofovir disoproxil (Viread) is used to treat HIV-1 infection and chronic hepatitis B.

Before taking this medicine

You should not take Vemlidy if you are allergic to tenofovir.

Do not take Vemlidy together with adefovir (Hepsera), or with combination medicines that contain tenofovir (Atripla, Biktarvy, Cimduo, Complera, Descovy, Genvoya, Odefsey, Stribild, Symfi, or Truvada).

To make sure this medicine is safe for you, tell your doctor if you have:

  • liver disease (especially hepatitis B if you also have HIV);

  • HIV;

  • kidney disease; or

  • low bone mineral density.

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 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.

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.

How should I take Vemlidy?

Before you start treatment with Vemlidy, your doctor may perform tests to make sure you do not have HIV.

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

The recommended dosage of Vemlidy is one 25mg tablet taken once a day at the same time each day. Take with food.

Carefully follow all instructions on your medicine label.

Do not stop using Vemlidy without first talking to your doctor.

Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.

Swallow the tablet whole and do not crush, chew, or break it. Tell your doctor if you have trouble swallowing a tablet.

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

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

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

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 to avoid

Avoid drinking alcohol. It may increase your risk of liver damage.

Taking this medicine will not prevent you from passing hepatitis B to other people.

Vemlidy side effects

Get emergency medical help if you have signs of an allergic reaction to Vemlidy: hives; difficulty 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:

  • sore throat, flu symptoms, easy bruising or unusual bleeding;

  • kidney problems - little or no urination, painful or difficult urination, swelling in your feet or ankles, feeling tired or short of breath; or

  • liver problems - swelling around your midsection, upper stomach pain, unusual tiredness, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

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, night 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 Vemlidy side effects may include:

  • stomach pain, nausea, vomiting, diarrhea;

  • fever, pain;

  • weakness, dizziness;

  • headache;

  • depressed mood;

  • itching, rash; or

  • sleep problems (insomnia).

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.

What other drugs will affect Vemlidy?

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.

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).

Many drugs can interact with tenofovir. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

Vemlidy (tenofovir alafenamide) and Viread (Tenofovir disproxil fumarate) are antiviral medications marketed by Gilead Sciences. They are both prodrugs of tenofovir.
Vemlidy and Viread are similar in terms of their effectiveness, but Vemlidy is effective at a much lower dose than Viread. Less tenofovir ends up in the bloodstream after taking Vemlidy, leading to improved renal and bone laboratory safety parameters compared with Viread.

Vemlidy also has greater plasma stability, enabling it to deliver tenofovir to hepatocytes more efficiently.

Vemlidy and Viread are both used to treat chronic hepatitis B virus (HBV) infection, but Viread is also used in the treatment of human immunodeficiency virus-1 (HIV-1) infection.

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Vemlidy only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.