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Uses

What is entecavir used for?

Entecavir is commonly used to treat chronic hepatitis B, a type of liver infection.

Entecavir may also be used for other conditions as determined by your healthcare provider.

How does entecavir work (mechanism of action)?

People with hepatitis B have a virus that spreads in their body and damages the liver. Entecavir helps stop the spread of hepatitis B in your body. 

How is entecavir supplied (dosage forms)?

Brands and other names

  • Baraclude

Dosage forms and strengths

  • 0.5 mg, 1 mg oral tablets
  • 0.05 mg/mL oral solution

How should I store entecavir?

Entecavir should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store tightly closed in a cool, dry place. Keep entecavir in the original carton container to protect from light. 

Side Effects

What are the most common side effects of entecavir?

The most common side effects of entecavir are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Headache
  • Feeling tired
  • Dizziness
  • Nausea

There may be other side effects of entecavir that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of entecavir?

While less common, the most serious side effects of entecavir are described below, along with what to do if they happen.

Lactic Acidosis. Entecavir may cause lactic acidosis (a buildup of lactic acid in your blood), which can be serious. Stop taking entecavir and get help right away if you have any of the following symptoms of lactic acidosis.

  • General ill feeling
  • Muscle pain
  • Difficulty breathing
  • Drowsiness or dizziness
  • Stomach pain, nausea, or vomiting
  • Fast or irregular heartbeat

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking entecavir. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Severe Allergic Reactions. Entecavir may cause allergic reactions, which can be serious. Stop taking entecavir and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use entecavir?

Allergies to Ingredients. People who are allergic to any of the following should not take entecavir.

  • Baraclude
  • Entecavir
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific entecavir products they stock.

What should I know about entecavir before using it?

Do not take entecavir unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Take each dose of entecavir on an empty stomach (at least 2 hours after the previous meal and 2 hours before the next meal).

Do not share entecavir with other people, even if they have the same condition as you. It may harm them.

If you are taking the liquid form of entecavir, use the provided dosing spoon to accurately measure your dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Hold the provided dosing spoon upright and slowly fill it to the correct line for your dose. After each dose, rinse the spoon with water. Ask your healthcare provider if you have any questions on how to properly measure your dose.

Keep entecavir out of the reach of children.

Entecavir can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how entecavir can affect you.  

Entecavir does not prevent you from spreading the hepatitis B virus to other people through sex or contact with your blood. Talk to your healthcare provider about safe ways to protect your partner during sex and do not share personal items like toothbrushes or razors with other people.

Stopping entecavir can cause a serious flare-up, or worsening, of your hepatitis B. Do not run out of entecavir or stop taking it without talking to your healthcare provider first. If you stop taking entecavir, keep all appointments for blood work so your healthcare provider can check the health of your liver.

Before starting this medicine, your healthcare provider will likely test you for HIV. This is important because if you have HIV but do not know it, taking entecavir alone could cause the HIV infection to become resistant to treatment. Early and regular testing helps catch an infection early and helps prevent resistance. Use condoms and know your partner's HIV status. Regular testing for sexually transmitted infections (STIs) is also important.

What should I tell my healthcare provider before using entecavir?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if entecavir is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Liver problems, including taking medicine for a previous infection of hepatitis B
  • Kidney problems
  • HIV or AIDS

Other Medicines and Supplements. Entecavir may interact with other medicines and supplements. Before taking entecavir, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how entecavir could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take entecavir while you are pregnant or trying to get pregnant. If you become pregnant while taking entecavir, you can register for the Antiretroviral Pregnancy Registry by visiting www.apregistry.com. This registry collects safety information about the use of antiretroviral medicines during pregnancy.

Breastfeeding. It is not known if entecavir passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take entecavir while breastfeeding.

Interactions

Does entecavir interact with foods or drinks?

There are no known interactions between entecavir and foods or drinks.

 It is unknown if drinking alcohol will affect entecavir. The risk of dizziness may be increased if you drink alcohol while taking entecavir. 

Does entecavir interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. 

In particular, make sure you discuss if you are using any of the following before taking entecavir.

  • A nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen, naproxen, and others, which is in many prescription and OTC products for pain, swelling, and fever
  • An angiotensin-converting enzyme (ACE) inhibitor, such as enalapril or lisinopril, which is a medicine for high blood pressure, heart failure, and certain kidney problems
  • An angiotensin II receptor blocker (ARB), such as losartan or valsartan, which is a medicine for high blood pressure, heart failure, and other heart conditions
  • A diuretic, also called a water pill, which is a medicine used to reduce edema (fluid retention) and blood pressure
  • Methotrexate (Trexall and others), which is a medicine commonly used for rheumatoid arthritis or certain types of cancer

This may not be a complete list of medicines that can interact with entecavir. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much entecavir?

If you or someone else has used too much entecavir, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of entecavir?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

Missing doses of entecavir can cause it to not work as well over time. So it is very important not to miss or skip doses.