Entecavir Accord
Antiviral medicine for chronic hepatitis B virus infection
Quick facts about Entecavir Accord
Key takeaways about Entecavir Accord
- First-line treatment for chronic hepatitis B: Entecavir is recommended by EASL, AASLD, and WHO as a preferred first-line antiviral for chronic HBV infection
- Never stop without medical advice: Abruptly discontinuing entecavir can cause a severe hepatitis flare-up that may lead to liver failure
- High barrier to resistance: In treatment-naive patients, entecavir has a very low resistance rate (1.2% after 6 years of treatment)
- Dose adjustment for kidney problems: Patients with impaired kidney function may need a reduced dose or extended dosing interval
- Not for HIV co-infection without HIV treatment: Using entecavir alone in HIV co-infected patients can cause HIV drug resistance
What Is Entecavir Accord and What Is It Used For?
Entecavir Accord is an antiviral medicine that belongs to the class of nucleoside analogues. It contains the active substance entecavir and is used to treat chronic (long-term) hepatitis B virus (HBV) infection in adults and in children and adolescents aged 2 to under 18 years who weigh at least 10 kg.
Hepatitis B is a viral infection that targets the liver. The hepatitis B virus infects liver cells (hepatocytes) and uses them to replicate. Over time, chronic HBV infection can lead to progressive liver damage, including inflammation (hepatitis), scarring (fibrosis), severe scarring (cirrhosis), and in some cases, liver cancer (hepatocellular carcinoma). According to the World Health Organization, approximately 254 million people worldwide live with chronic hepatitis B, and it causes an estimated 1.1 million deaths annually, primarily from cirrhosis and liver cancer.
Entecavir works by blocking the hepatitis B virus polymerase enzyme, which the virus needs to replicate its DNA. By inhibiting this enzyme, entecavir dramatically reduces the amount of virus in the bloodstream (viral load), often to undetectable levels. This reduction in viral replication allows the liver to heal and reduces the progression of liver disease. Clinical studies have demonstrated that long-term entecavir therapy can reverse liver fibrosis and even early cirrhosis in many patients.
Entecavir Accord can be used in patients with both compensated liver disease (where the liver is damaged but still functions adequately) and decompensated liver disease (where the liver is severely damaged and cannot function properly). In patients with decompensated liver disease, treatment with entecavir can improve liver function scores and survival outcomes. The European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD) both recommend entecavir as a first-line treatment option for chronic hepatitis B.
Entecavir Accord does not cure hepatitis B, but it suppresses the virus effectively. Most patients require long-term treatment. Stopping entecavir without medical supervision can lead to a dangerous flare-up of liver inflammation. Your doctor will determine how long you need to take this medicine and will monitor your liver function regularly.
How does entecavir work in the body?
Entecavir is a guanosine nucleoside analogue. After oral administration, it is absorbed and then phosphorylated inside cells to its active triphosphate form. This active form competes with the natural building block deoxyguanosine triphosphate (dGTP) for incorporation into the viral DNA chain. When the active form of entecavir is incorporated instead of the natural nucleotide, it effectively halts the viral DNA replication process.
Entecavir inhibits three key activities of the HBV polymerase: the priming of the polymerase, the reverse transcription of the negative-strand DNA from the pregenomic messenger RNA, and the synthesis of the positive-strand HBV DNA. This comprehensive inhibition explains entecavir's potent antiviral activity and its high barrier to the development of drug resistance in patients who have not previously been treated with other nucleoside analogues.
Other brand names containing entecavir
Entecavir is the active ingredient found in several branded and generic products worldwide. Besides Entecavir Accord, the same active substance is available under brand names including Entecavir Viatris, Entecavir Medical Valley, Entecavir STADA, and Entecavir Amarox. The original branded product was Baraclude, manufactured by Bristol-Myers Squibb, which received initial approval from the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA). All products containing entecavir are bioequivalent and deliver the same therapeutic benefit.
What Should You Know Before Taking Entecavir Accord?
Before starting Entecavir Accord, inform your doctor about kidney problems, HIV status, pregnancy or breastfeeding plans, and all other medications you take. Do not take this medicine if you are allergic to entecavir or any of the other ingredients. Special precautions are needed for patients co-infected with HIV.
Contraindications
Do not take Entecavir Accord if you are allergic (hypersensitive) to entecavir or any of the other ingredients in this medicine. The inactive ingredients include calcium carbonate, pregelatinised starch, croscarmellose sodium, soy polysaccharides, citric acid monohydrate, and sodium stearyl fumarate. The tablet coating contains hypromellose, titanium dioxide (E171), macrogol, and polysorbate 80 (for 0.5 mg tablets) or red iron oxide E172 (for 1 mg tablets).
If you are allergic to soy, you should not take Entecavir Accord, as it contains soy polysaccharides. This is an important consideration that patients should discuss with their prescribing physician before starting treatment. Alternative formulations or other antiviral agents may be recommended for soy-allergic patients.
Warnings and Precautions
Talk to your doctor or pharmacist before taking Entecavir Accord in the following situations:
- Kidney problems: Entecavir is eliminated from the body through the kidneys. If you have impaired kidney function, your doctor may need to adjust the dose or the dosing interval. Your kidney function should be monitored regularly during treatment.
- Stopping treatment: Never stop taking Entecavir Accord without consulting your doctor. Abrupt discontinuation can cause a severe flare-up of hepatitis B that may lead to liver failure. When treatment is stopped, your doctor will monitor you with regular blood tests for at least several months.
- HIV co-infection: If you are also infected with HIV (human immunodeficiency virus), you must inform your doctor. You should not take Entecavir Accord for hepatitis B unless you are also receiving antiretroviral therapy for HIV. Using entecavir without concurrent HIV treatment may lead to the development of HIV resistance, which could compromise future HIV treatment options.
- Lactic acidosis risk: Entecavir belongs to a class of medicines that can cause lactic acidosis (excess lactic acid in the blood) and liver enlargement. Symptoms such as nausea, vomiting, and abdominal pain may indicate developing lactic acidosis. This rare but serious side effect has, in isolated cases, been fatal. Lactic acidosis occurs more frequently in women, particularly those who are significantly overweight.
- Transmission prevention: Treatment with entecavir does not prevent you from transmitting hepatitis B to others through sexual contact or body fluids (including blood). It is essential to continue using appropriate precautions, such as barrier protection and avoiding sharing needles. A highly effective vaccine is available for protecting people at risk of hepatitis B infection.
Stopping Entecavir Accord without medical supervision can cause a dangerous hepatitis B flare. This reactivation of the virus can lead to rapid liver deterioration and, in severe cases, acute liver failure. When treatment discontinuation is considered, your doctor will perform close follow-up with liver function tests and HBV DNA measurements for at least 6 months after stopping.
Pregnancy and Breastfeeding
Tell your doctor if you are pregnant or planning to become pregnant. The safety of Entecavir Accord during pregnancy has not been established. Entecavir should not be used during pregnancy unless your doctor specifically determines that the benefit outweighs the potential risk. Women of childbearing age who are being treated with Entecavir Accord should use effective contraception to avoid becoming pregnant.
Breastfeeding mothers should not breastfeed while taking Entecavir Accord. It is not known whether entecavir passes into breast milk. If you are breastfeeding, your doctor will discuss alternative feeding options or alternative treatment approaches.
Current international guidelines from EASL (2024) recommend tenofovir disoproxil fumarate (TDF) as the preferred antiviral for pregnant women with chronic hepatitis B who require treatment, due to its more extensive safety data in pregnancy. Your healthcare provider will advise you on the most appropriate treatment if you are pregnant or planning a pregnancy.
Children and Adolescents
Entecavir Accord can be used in children and adolescents aged 2 to under 18 years who weigh at least 10 kg and have compensated liver disease. The dose is determined by the child's body weight. Children weighing at least 32.6 kg can take the 0.5 mg tablet. For children weighing between 10 and 32.5 kg, an oral solution formulation of entecavir may be available. Entecavir should not be used in children under 2 years of age or those weighing less than 10 kg.
Driving and Using Machines
Dizziness, fatigue, and drowsiness are common side effects of entecavir that may impair your ability to drive vehicles or operate machinery. If you experience these symptoms, you should avoid driving or using machines until you know how the medicine affects you. Discuss any concerns with your doctor.
How Does Entecavir Accord Interact with Other Drugs?
Entecavir has relatively few drug interactions. The main concern is with medicines that affect kidney function or compete for renal tubular secretion, as entecavir is primarily eliminated through the kidneys. Always tell your doctor about all medicines you are taking, including over-the-counter products and supplements.
Since entecavir is primarily eliminated through the kidneys by a combination of glomerular filtration and active tubular secretion, co-administration with drugs that reduce kidney function or compete for active tubular secretion may increase blood levels of either entecavir or the co-administered drug. This could potentially lead to increased side effects. Your doctor should be aware of all medicines you are taking so that appropriate monitoring can be arranged.
| Drug/Class | Type of Interaction | Clinical Significance | Recommendation |
|---|---|---|---|
| Nephrotoxic drugs (e.g., aminoglycosides, ciclosporin, tacrolimus, NSAIDs) | Reduced renal clearance of entecavir | Moderate | Monitor renal function closely; dose adjustment may be needed |
| Drugs competing for tubular secretion (e.g., ribavirin) | Increased plasma levels of either drug | Moderate | Monitor for increased side effects |
| Lamivudine | Cross-resistance concerns | Major | Lamivudine-resistant patients require 1 mg dose of entecavir; take on empty stomach |
| Adefovir dipivoxil | No significant pharmacokinetic interaction | Low | Can be used sequentially; monitor for resistance patterns |
| Tenofovir disoproxil / alafenamide | No significant pharmacokinetic interaction | Low | Combination or switch possible under medical supervision |
Food Interactions
In most cases, Entecavir Accord can be taken with or without food. However, there are important exceptions. If you have previously been treated with a medicine containing lamivudine and switched to Entecavir Accord because lamivudine treatment was insufficiently effective, you should take Entecavir Accord on an empty stomach. Similarly, if your liver disease is very advanced (decompensated liver disease), your doctor may instruct you to take Entecavir Accord on an empty stomach.
Taking the medicine on an empty stomach means at least 2 hours after a meal and at least 2 hours before the next meal. This is because food can reduce the absorption of entecavir and lower blood levels in these specific patient populations where optimal drug levels are particularly important.
Children and adolescents aged 2 to under 18 years can take Entecavir Accord with or without food regardless of their treatment history.
What Is the Correct Dosage of Entecavir Accord?
The standard adult dose is 0.5 mg once daily for treatment-naive patients or 1 mg once daily for lamivudine-resistant patients. Dose adjustments are required for patients with impaired kidney function. Children's dose is weight-based. Always take the dose prescribed by your doctor.
Not all patients take the same dose of Entecavir Accord. The dose depends on whether you have been treated for hepatitis B before (and with which medicine), your kidney function, and the condition of your liver. Always take this medicine exactly as your doctor has instructed. Your doctor will determine the appropriate dose and duration of treatment for your individual situation.
Adults
Standard dosing for adults
| Patient Type | Dose | Frequency | Food Requirements |
|---|---|---|---|
| Treatment-naive (never treated before, or compensated liver disease) | 0.5 mg | Once daily | With or without food |
| Lamivudine-resistant (previous lamivudine failure) | 1 mg | Once daily | On empty stomach (2h before/after meals) |
| Decompensated liver disease | 1 mg | Once daily | On empty stomach (2h before/after meals) |
Children and Adolescents (aged 2 to under 18 years)
The dose for children is determined by body weight. Children weighing at least 32.6 kg can take the 0.5 mg film-coated tablet. For children weighing between 10 and 32.5 kg, an oral solution formulation of entecavir is recommended, as the tablet cannot be divided to achieve the correct lower dose. The child's doctor will calculate the appropriate dose. All doses are taken once daily and can be given with or without food.
Entecavir is not recommended for children under 2 years of age or children weighing less than 10 kg due to insufficient safety and efficacy data in this population.
Patients with Kidney Problems
If you have reduced kidney function, your doctor may prescribe a lower dose or instruct you to take the medicine less frequently than once daily. The specific adjustment depends on your creatinine clearance, which is a measure of how well your kidneys are filtering waste products. Your doctor will determine the appropriate dose modification based on your kidney function test results. Regular monitoring of kidney function is recommended during treatment.
Missed Dose
If you forget to take a dose of Entecavir Accord, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, skip the missed dose and take the next dose at the regular time. Do not take a double dose to make up for a forgotten dose. It is important to try to take your medicine at the same time each day to maintain consistent blood levels of the drug.
Overdose
If you take more Entecavir Accord than prescribed, contact your doctor immediately or go to the nearest emergency department. Bring the medicine package with you so the medical team knows exactly what you have taken and how much. There is limited clinical experience with overdose of entecavir; however, healthy volunteers who received single doses up to 40 mg or multiple doses of up to 20 mg daily for up to 14 days did not experience unexpected adverse effects.
What Are the Side Effects of Entecavir Accord?
Common side effects of Entecavir Accord include headache, fatigue, dizziness, nausea, and elevated liver enzymes. Serious but rare side effects include lactic acidosis (excess lactic acid in the blood) and severe allergic reactions. Contact your doctor if you experience persistent nausea, vomiting, or unusual tiredness.
Like all medicines, Entecavir Accord can cause side effects, although not everybody gets them. The side effects reported with entecavir are generally mild to moderate in severity. Most side effects resolve on their own as your body adjusts to the medicine, or they can be managed with appropriate medical care. Below is a summary of the known side effects, organized by how frequently they occur.
Side effects in adults
Common
- Headache
- Insomnia (difficulty sleeping)
- Fatigue (tiredness)
- Dizziness
- Drowsiness (somnolence)
- Nausea
- Vomiting
- Diarrhea
- Dyspepsia (indigestion, discomfort after meals)
- Elevated liver enzyme levels in blood tests
Uncommon
- Skin rash
- Hair loss (alopecia)
Rare
- Severe allergic reactions (anaphylaxis)
- Lactic acidosis (excess lactic acid in the blood)
Side effects in children and adolescents
The side effects experienced by children and adolescents are similar to those seen in adults, with one notable difference:
Very Common (in children)
- Neutropenia – low levels of neutrophils (a type of white blood cell that is important in fighting infections)
Neutropenia in children being treated with entecavir is generally mild and reversible. Your child's doctor will perform regular blood tests to monitor white blood cell counts during treatment and will advise on any necessary precautions or dose adjustments.
Lactic acidosis is a rare but potentially life-threatening complication associated with nucleoside analogues, including entecavir. Symptoms may include persistent nausea, vomiting, abdominal pain, unexplained weight loss, rapid or difficult breathing, muscle cramps, and unusual tiredness or weakness. This condition occurs more frequently in women, particularly those who are significantly overweight. If you experience any of these symptoms, seek immediate medical attention.
Hepatitis flare after stopping treatment
Although not a side effect of the medicine itself, stopping entecavir treatment can cause a severe exacerbation of hepatitis B. This happens because the virus, which has been suppressed during treatment, can rapidly replicate again once the antiviral is removed. Symptoms of a hepatitis flare include fatigue, abdominal pain, jaundice (yellowing of the skin and eyes), dark urine, and significantly elevated liver enzymes in blood tests. This is why your doctor will monitor your liver function closely for several months after stopping treatment.
How Should You Store Entecavir Accord?
Store Entecavir Accord at room temperature, away from direct light and moisture. Keep it out of reach of children. Do not use after the expiry date on the packaging. If supplied in a bottle, use within 90 days of opening.
Proper storage of medicines is essential to maintain their safety and effectiveness. Entecavir Accord does not require any special storage conditions – simply store it at room temperature. Keep the medicine in its original packaging to protect it from moisture and light.
Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date printed on the blister, bottle, or carton after "EXP." The expiry date refers to the last day of that month. If the medicine is supplied in a bottle, use the tablets within 90 days after first opening.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to properly dispose of medicines that are no longer needed. These measures help to protect the environment and prevent accidental ingestion by children or animals.
What Does Entecavir Accord Contain?
Each Entecavir Accord tablet contains entecavir monohydrate equivalent to 0.5 mg or 1 mg of entecavir. The tablets also contain inactive ingredients including calcium carbonate, soy polysaccharides, and various excipients. The 0.5 mg tablets are white and triangular; the 1 mg tablets are pink and triangular.
Active ingredient
The active substance is entecavir. Each Entecavir Accord 0.5 mg film-coated tablet contains entecavir monohydrate equivalent to 0.5 mg entecavir. Each Entecavir Accord 1 mg film-coated tablet contains entecavir monohydrate equivalent to 1 mg entecavir.
Inactive ingredients
The tablet core contains: calcium carbonate, pregelatinised starch, croscarmellose sodium, soy polysaccharides, citric acid monohydrate, and sodium stearyl fumarate.
The tablet coating for the 0.5 mg tablets contains: hypromellose, titanium dioxide (E171), macrogol, and polysorbate 80. The tablet coating for the 1 mg tablets contains: hypromellose, titanium dioxide (E171), macrogol, and red iron oxide (E172).
This medicine contains soy polysaccharides. If you are allergic to soy, you should not use this medicine. This medicine contains less than 1 mmol (23 mg) sodium per tablet, meaning it is essentially sodium-free.
Appearance and packaging
Entecavir Accord 0.5 mg tablets are white to off-white, triangular, biconvex film-coated tablets imprinted with "J" on one side and "110" on the other side. Entecavir Accord 1 mg tablets are pink, triangular, biconvex film-coated tablets imprinted with "J" on one side and "111" on the other side.
Entecavir Accord is available in cartons containing 30 × 1 or 90 × 1 film-coated tablets (in unit-dose blisters) and in bottles containing 30 film-coated tablets. Not all pack sizes may be available in all countries.
Frequently Asked Questions About Entecavir Accord
Entecavir Accord is used to treat chronic (long-term) hepatitis B virus infection. It is an antiviral medicine that reduces the amount of virus in the body and helps improve the condition of the liver. It is approved for use in adults and in children aged 2 years and older who weigh at least 10 kg. It can be used in patients with compensated liver disease (liver damaged but still functioning) and decompensated liver disease (liver severely damaged).
No, you should never stop taking Entecavir Accord without your doctor's guidance. Stopping treatment abruptly can cause a severe flare-up of hepatitis B, potentially leading to serious liver damage or liver failure. When discontinuation is being considered, your doctor will plan a gradual approach with close monitoring of your liver function through blood tests for at least 6 months afterward.
No, Entecavir Accord does not cure hepatitis B. It effectively suppresses the virus to very low or undetectable levels, which helps the liver heal and prevents further damage. Most patients require long-term or indefinite treatment. Discontinuation may only be considered under strict medical supervision when specific criteria are met, such as sustained loss of hepatitis B surface antigen (HBsAg). Your doctor will determine the appropriate treatment duration for your individual case.
Entecavir Accord should generally not be used during pregnancy as its safety has not been established. Women of childbearing age should use effective contraception while taking this medicine. If you become pregnant while on treatment, contact your doctor immediately. Current guidelines recommend tenofovir disoproxil fumarate (TDF) as the preferred antiviral option during pregnancy due to its more extensive safety data. Breastfeeding is also not recommended during treatment.
If you are co-infected with both hepatitis B and HIV, you should not take Entecavir Accord for hepatitis B unless you are also receiving antiretroviral therapy for HIV. Using entecavir alone in HIV co-infected patients can lead to the development of HIV drug resistance, which may reduce the effectiveness of future HIV treatments. Always inform your doctor about all infections you have so that the most appropriate treatment plan can be designed.
If you miss a dose, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take two doses at the same time or take a double dose to compensate for a missed one. Try to take your medicine at the same time each day to help you remember and to maintain consistent blood levels of the drug.
References
All information on this page is based on official prescribing information and international peer-reviewed medical guidelines. No commercial funding or pharmaceutical sponsorship influences our content.
- European Medicines Agency (EMA). Entecavir Accord – Summary of Product Characteristics (SmPC). Available at: www.ema.europa.eu.
- European Association for the Study of the Liver (EASL). EASL 2024 Clinical Practice Guidelines on the Management of Hepatitis B Virus Infection. Journal of Hepatology. 2024.
- Terrault NA, Lok ASF, McMahon BJ, et al. Update on Prevention, Diagnosis, and Treatment of Chronic Hepatitis B: AASLD 2023 Hepatitis B Guidance. Hepatology. 2023.
- World Health Organization (WHO). Guidelines for the Prevention, Diagnosis, Care and Treatment for People with Chronic Hepatitis B Infection. WHO; 2024.
- Chang TT, Lai CL, Kew Yoon S, et al. Entecavir treatment for up to 5 years in patients with hepatitis B e antigen-positive chronic hepatitis B. Hepatology. 2010;51(2):422-430.
- Tenney DJ, Rose RE, Baldick CJ, et al. Long-term monitoring shows hepatitis B virus resistance to entecavir in nucleoside-naïve patients is rare through 5 years of therapy. Hepatology. 2009;49(5):1503-1514.
- Lok AS, McMahon BJ, Brown RS, et al. Antiviral therapy for chronic hepatitis B viral infection in adults: A systematic review and meta-analysis. Hepatology. 2016;63(1):284-306.
- British National Formulary (BNF). Entecavir. National Institute for Health and Care Excellence (NICE). Available at: bnf.nice.org.uk.
Editorial Team
This article has been written and reviewed by iMedic's medical editorial team, which includes specialist physicians in hepatology, gastroenterology, and clinical pharmacology. All content follows our strict editorial standards and is based on the latest international guidelines and peer-reviewed evidence.