Entecavir

Entecavir is a prescription medicine used to treat chronic (long term) hepatitis B virus (swelling of the liver caused by a virus) in adults and children 2 years of age and older who have active liver damage. 

Entecavir belongs to a group of drugs called nucleoside analogs. It works by decreasing the amount of virus in the body.

Entecavir is a prescription medicine used to treat chronic (long-term) hepatitis B virus (swelling of the liver caused by a virus) in adults and children 2 years of age and older who have active liver damage.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Entecavir may be found in some form under the following brand names:

• Baraclude

Entecavir may cause serious side effects. See “Drug Precautions”.

The most common side effects of entecavir include:

• headache
• tiredness
• dizziness
• nausea

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of entecavir. For more information, ask your healthcare provider or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your healthcare provider about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.

Know the medicines you take. Keep a list of your medicines with you to show your healthcare provider and pharmacist when you get a new medicine.

Your hepatitis B virus infection may get worse if you stop taking entecavir. This usually happens within 6 months after stopping entecavir.

• Take entecavir exactly as prescribed.
• Do not run out of entecavir.
• Do not stop entecavir without talking to your healthcare provider.
• Your healthcare provider should monitor your health and do regular blood tests to check your liver if you stop taking entecavir.

If you have or get HIV that is not being treated with medicines while taking entecavir, the HIV virus may develop resistance to certain HIV medicines and become harder to treat. You should get an HIV test before you start taking entecavir and anytime after that when there is a chance you were exposed to HIV.

Entecavir can cause serious side effects including lactic acidosis and serious liver problems.

Lactic acidosis (buildup of acid in the blood). Some people who have taken entecavir or medicines like entecavir (a nucleoside analogue) have developed a serious condition called lactic acidosis. Lactic acidosis is a serious medical emergency that can cause death. Lactic acidosis must be treated in the hospital. Reports of lactic acidosis with entecavir generally involved patients who were seriously ill due to their liver disease or other medical condition.

Call your healthcare provider right away if you get any of the following signs or symptoms of lactic acidosis:

• You feel very weak or tired.
• You have unusual (not normal) muscle pain.
• You have trouble breathing.
• You have stomach pain with nausea and vomiting.
• You feel cold, especially in your arms and legs.
• You feel dizzy or light-headed.
• You have a fast or irregular heartbeat.

Serious liver problems. Some people who have taken medicines like entecavir have developed serious liver problems called hepatotoxicity, with liver enlargement (hepatomegaly) and fat in the liver (steatosis). Hepatomegaly with steatosis is a serious medical emergency that can cause death.

Call your healthcare provider right away if you get any of the following signs or symptoms of liver problems:

• Your skin or the white part of your eyes turns yellow (jaundice).
• Your urine turns dark.
• Your bowel movements (stools) turn light in color.
• You don’t feel like eating food for several days or longer.
• You feel sick to your stomach (nausea).
• You have lower stomach pain.

You may be more likely to get lactic acidosis or serious liver problems if you are female, very overweight, or have been taking nucleoside analogue medicines, like entecavir, for a long time.

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of entecavir there are no specific foods that you must exclude from your diet when receiving this medication.

Before you take entecavir, tell your healthcare provider if you:

• have kidney problems. Your entecavir dose or schedule may need to be changed.
• have received medicine for HBV before. Some people, especially those who have already been treated with certain other medicines for HBV infection, may develop resistance to entecavir. These people may have less benefit from treatment with entecavir and may have worsening of hepatitis after resistant virus appears. Your healthcare provider will test the level of the hepatitis B virus in your blood regularly.
• have any other medical conditions.
• are pregnant or breastfeeding

Tell your healthcare provider about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Entecavir falls into category C. There are no well-done studies that have been done in humans with entecavir. But in animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.

• Pregnancy Registry. If you take entecavir while you are pregnant, talk to your healthcare provider about how you can take part in the Pregnancy Registry. The purpose of the pregnancy registry is to collect information about the health of you and your baby.

Tell your healthcare provider if you are breastfeeding or plan to breastfeed.

It is not known if entecavir crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using entecavir.

• Take entecavir exactly as your healthcare provider tells you to.
• Your healthcare provider will tell you how much entecavir to take.
• Your healthcare provider will tell you when and how often to take entecavir.
• Take entecavir on an empty stomach, at least 2 hours after a meal and at least 2 hours before the next meal.
• If you are taking entecavir oral solution, carefully measure your dose with the spoon provided, as follows:
  • Hold the spoon in a vertical (upright) position and fill it gradually to the mark corresponding to the prescribed dose. Holding the spoon with the volume marks facing you, check that it has been filled to the proper mark.
  • Swallow the medicine directly from the measuring spoon.
  • After each use, rinse the spoon with water and allow it to air dry.
  • If you lose the spoon, call your pharmacist or healthcare provider for instructions.

• Do not change your dose or stop taking entecavir without talking to your healthcare provider.
• If you forget to take entecavir, take it as soon as you remember and then take your next dose at its regular time. If it is almost time for your next dose, skip the missed dose. Do not take two doses at the same time. Call your healthcare provider or pharmacist if you are not sure what to do.
• When your supply of entecavir starts to run low, call your healthcare provider or pharmacy for a refill. Do not run out of entecavir.

If you take too much entecavir, call your healthcare provider or go to the nearest emergency room right away.

• Store entecavir tablets or oral solution at room temperature, between 59° F to 86° F (15° C to 30° C).
• Keep entecavir tablets in a tightly closed container.
• Do not store entecavir tablets in a damp place such as a bathroom medicine cabinet or near the kitchen sink.
• Store entecavir oral solution in the original carton, and keep entecavir oral solution out of the light.
• Safely throw away entecavir that is out of date or no longer needed. Dispose of unused medicines through community take-back disposal programs when available or place entecavir in an unrecognizable closed container in the household trash.

Keep entecavir and all medicines out of the reach of children.

WARNINGS: SEVERE ACUTE EXACERBATIONS OF HEPATITIS B, PATIENTS CO-INFECTED WITH HIV AND HBV, and LACTIC ACIDOSIS AND HEPATOMEGALY

Severe acute exacerbations of hepatitis B have been reported in patients who have discontinued anti-hepatitis B therapy, including entecavir. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue anti-hepatitis B therapy. If appropriate, initiation of anti-hepatitis B therapy may be warranted.

Limited clinical experience suggests there is a potential for the development of resistance to HIV (human immunodeficiency virus) nucleoside reverse transcriptase inhibitors if entecavir is used to treat chronic hepatitis B virus (HBV) infection in patients with HIV infection that is not being treated. Therapy with entecavir is not recommended for HIV/HBV co-infected patients who are not also receiving highly active antiretroviral therapy (HAART).

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination with antiretrovirals.