Rarely, entecavir may cause serious (possibly fatal) liver problems and lactic acid build-up in the blood (lactic acidosis). Get medical help right away if you have any of the following symptoms: nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine, unusual tiredness/weakness, deep/fast breathing, unusual drowsiness, unusual muscle pain, feeling cold in your arms/legs, fast/irregular heartbeat. These side effects may occur more often in women and obese patients.
Your hepatitis B infection may get worse if you stop taking entecavir. Do not stop this medication without talking to your doctor. Your doctor will do blood tests to check your liver for several months after you stop entecavir.
This medication is not recommended if you have both HIV and hepatitis B and are not receiving effective treatment for HIV. This drug does not treat HIV, and it can cause certain HIV medications to become ineffective. Get an HIV test before starting this medication, and get tested again anytime you may have become infected. Consult your doctor for more details.
See also Warning section.
Entecavir is used to treat long-term hepatitis B infection. Hepatitis B is an infection of the liver caused by the hepatitis B virus. Long-term infection can cause liver damage, rarely liver cancer, and liver failure. Entecavir helps to decrease the amount of hepatitis B virus in your body. It is unknown if this medication lowers your chance of getting liver cancer or liver damage. Entecavir is an antiviral that belongs to a class of drugs known as hepatitis B virus nucleoside reverse transcriptase inhibitors.
Entecavir is not a cure for hepatitis B. It does not prevent the spread of the virus to others through sexual contact or blood/body fluid contamination (such as sharing used needles).
Read the Patient Information Leaflet provided by your pharmacist before you start taking entecavir and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
If you are taking entecavir oral liquid, carefully measure your dose with the medicine spoon provided. Do not use a household spoon because you may not get the correct dose. Swallow the medicine directly from the measuring spoon. Do not mix the medication with water or other liquids. Rinse the spoon with water after each use.
The dosage is based on your medical condition and response to treatment. For children, the dosage is also based on weight.
It is very important to continue taking this medication exactly as prescribed by your doctor. Do not skip any doses.
This medication works best when the amount of drug in your body is kept at a constant level. Take this drug at evenly spaced intervals. To help you remember, take it at the same time each day.
Do not take more or less of this drug than prescribed or stop taking it even for a short time unless directed to do so by your doctor. Doing so may cause the amount of virus to increase, make the infection more difficult to treat (resistant), or worsen side effects. See also Warning section.
Tell your doctor if your condition does not get better or if it gets worse.
See also Warning section.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking entecavir, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: HIV infection, kidney disease, other hepatitis B drugs taken in the past.
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely.
Avoid alcohol because it may worsen dizziness and liver problems.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
To decrease your risk of spreading hepatitis B to others, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.
During pregnancy, this medication should be used only when clearly needed. It is not known if this medication helps to prevent the hepatitis B virus from passing from the mother to the baby. Discuss the risks and benefits with your doctor.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share this medication with others.
Lab and/or medical tests (such as liver tests, virus levels) should be done while you are taking this medication. Keep all medical and lab appointments.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
Store at room temperature away from light and moisture. To protect from light, store the bottle of medication in the original carton. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised July 2016. Copyright(c) 2016 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet