Entecavir .5 mg Tablet, 30-count — NDC 51407-589-30 (Billing 51407-0589-30)
This is a package of 30 tablets of Entecavir .5 mg Tablet from Golden State Medical Supply, Inc., marketed since Nov 2021 and currently FDA-listed. It is this product's only package size.
Other active recalls for Entecavir (different manufacturers) — 4 · tap to view
Identity & classification
Regulatory identifiers FDA, NLM and CMS codes for this package
Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification
- GSN (GCN sequence number): 058934
- GCN: 24466
- HICL (First Databank): 032832
- AHFS class code: 08:18.32.00
- RxCUI (RxNorm): 485434
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
- RxNorm (NLM RxNav) · catalog refreshed Oct 1, 2026
- Medi-Span GPI (licensed)
- First Databank (licensed) · refreshed Oct 1, 2026
RxNorm drug class
This medicine belongs to the Hepatitis B Virus Nucleoside Analog Reverse Transcriptase Inhibitor class.
Where does this data come from?
- RxClass (NLM) · catalog refreshed Oct 1, 2026
Clinical
Entecavir is used to treat chronic (long-term) hepatitis B infection (swelling of the liver caused by a virus) in adults and children 2 years of age and older who have liver damage. Entecavir is in a class of medications called nucleoside analogs. It works by decreasing the amount of hepatitis B virus (HBV) in the body. Entecavir does not cure HBV and may not prevent complications of chronic hepatitis B such as cirrhosis of the liver or liver cancer. Entecavir does not prevent the spread of HBV to other people.
Read the full MedlinePlus article ↗- Entecavir keeps the hepatitis B virus under control by stopping it from copying itself, which protects your liver from ongoing damage. It's not a cure — it doesn't permanently clea...
- What exactly is entecavir treating — is it curing my hepatitis B?
- Yes, timing really does matter here. You need to take entecavir on an empty stomach — at least 2 hours after eating and at least 2 hours before your next meal. Studies showed that...
- Does it matter when I take it — can I take it with breakfast?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Entecavir — tap one for details:
Where does this data come from?
- MedlinePlus (NLM) · refreshed Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
Ask a licensed pharmacist directly — free, answered by our team.
Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $1.76 | $52.74 / 30 tablets |
Where does this data come from?
- CMS NADAC weekly file
- CMS ASP pricing files · refreshed Sep 20, 2026
- CMS Medicaid State Drug Utilization Data · refreshed Oct 2, 2026
- CMS Part D plan pricing files · refreshed Sep 24, 2026
- VA National Acquisition Center price file
Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Marketing end | Status |
|---|---|---|---|---|
| 51407-0589-30 You're viewing this Main listing | 30 TABLET in 1 BOTTLE, PLASTIC | 2024-08-26 | — | Active |
Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Entecavir .5 mg 16714-0717-01 | NorthStar | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 31722-0833-30 | Camber | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 42494-0457-30 | Cameron | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 42806-0658-30 | EPIC | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 42806-0667-30 | Epic | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 43547-0436-03 | Solco | 30 tablets | $0.219 | — | Availability likely | — |
| Entecavir .5 mg 60687-0216-25 | American | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 61442-0311-30 | Carlsbad | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 65862-0841-30 | Aurobindo | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 69097-0426-02 | Cipla | 30 tablets | $0.219 | AB | Availability likely | — |
| Entecavir .5 mg 65162-0446-03 | Amneal | 30 tablets | $1.077 | AB | FDA listed | — |
| Baraclude .5 mg 00003-1611-12 | E.R. | 30 tablets | $44.187 | AB | Availability likely | — |
| Entecavir .5 mg 42291-0261-30 | AvKARE | 30 tablets | — | AB | FDA listed | — |
| Entecavir .5 mg 50771-0013-01 | Yaopharma | 30 tablets | — | — | FDA listed | — |
| Entecavir .5 mgthis 51407-0589-30 | Golden | 30 tablets | — | AB | FDA listed | — |
| Entecavir .5 mg 68382-0920-01 | Zydus | 100 tablets | — | AB | FDA listed | — |
| Entecavir .5 mg 70771-1019-01 | Zydus | 100 tablets | — | AB | FDA listed | — |
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA Orange Book · refreshed Sep 3, 2026
- CMS NADAC weekly file
Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
Where does this data come from?
- FDA Orange Book · refreshed Sep 3, 2026
What it looks like
Where does this data come from?
- FDA label on DailyMed · label index refreshed Oct 1, 2026
Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII 2S7830E561
Crospovidone is a synthetic polymer derived from povidone. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the active ingredient can be absorbed.
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UNII R75537T0T4
Hypromellose 2910 is a plant-derived thickening agent made from cellulose. It serves as a binder that holds tablet ingredients together, a film-coating for pills, and a viscosity controller in liquids.
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UNII EWQ57Q8I5X
Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII OP1R32D61U
Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
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UNII B697894SGQ
Polyethylene glycol 400 is a clear, thick liquid made from petroleum-derived polymers. It acts as a solvent and humectant in medicines, helping dissolve active ingredients and retain moisture in the formulation.
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UNII U725QWY32X
Povidone K30 is a synthetic polymer made from petroleum. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in the stomach so the medicine can be absorbed.
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UNII 15FIX9V2JP
Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
8 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.- FDA label on DailyMed · label index refreshed Oct 1, 2026
- FDA openFDA NDC Directory · synced Oct 1, 2026
Inactive ingredient FAQ
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Manufacturer & labeler
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- Drugs@FDA
Full prescribing information FDA SPL
🚨 Boxed Warning ▾
These highlights do not include all the information needed to use ENTECAVIR TABLETS safely and effectively. See full prescribing information for ENTECAVIR TABLETS. Initial U.S.
Approval: 2005 FULL PRESCRIBING INFORMATION WARNING: 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 [see Warnings and Precautions (5.1)].
Limited clinical experience suggests there is a potential for the development of resistance to HIV (human immunodeficiency virus) nucleoside reverse transcriptase inhibitors if entecavir tablets are used to treat chronic hepatitis B virus (HBV) infection in patients with HIV infection that is not being treated. Therapy with entecavir tablets are not recommended for HIV/HBV co-infected patients who are not also receiving highly active antiretroviral therapy (HAART) [see Warnings and Precautions (5.2)]. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogue inhibitors alone or in combination with antiretrovirals [see Warnings and Precautions (5.3)].
HIGHLIGHTS OF PRESCRIBING INFORMATION These highlights do not include all the information needed to use ENTECAVIR TABLETS safely and effectively. See full prescribing information for ENTECAVIR TABLETS. ENTECAVIR tablets, for oral use Initial U.S.
Approval: 2005 WARNING: SEVERE ACUTE EXACERBATIONS OF HEPATITIS B, PATIENTS CO-INFECTED WITH HIV AND HBV, and LACTIC ACIDOSIS AND HEPATOMEGALY See full prescribing information for complete boxed warning. ● 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 for at least several months after discontinuation. Initiation of anti-hepatitis B therapy may be warranted.
(5.1) ● Entecavir tablets are not recommended for patients co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) who are not also receiving highly active antiretroviral therapy (HAART), because of the potential for the development of resistance to HIV nucleoside reverse transcriptase inhibitors. (5.2) ● Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogue inhibitors. (5.3)
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE Entecavir tablets are indicated for the treatment of chronic hepatitis B virus infection in adults and pediatric patients 2 years of age and older with evidence of active viral replication and either evidence of persistent elevations in serum aminotransferases (ALT or AST) or histologically active disease. Entecavir is a hepatitis B virus nucleoside analogue reverse transcriptase inhibitor indicated for the treatment of chronic hepatitis B virus infection in adults and children at least 2 years of age with evidence of active viral replication and either evidence of persistent elevations in serum aminotransferases (ALT or AST) or histologically active disease.
( 1)
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION
2.1 Timing of Administration
2.4 Renal Impairment
2.2 Recommended Dosage in Adults
2.5 Hepatic Impairment
2.3 Recommended Dosage in Pediatric Patients
2.6Duration of Therapy ● Nucleoside-inhibitor-treatment-naïve with compensated liver disease (greater than or equal to 16 years old): 0.5 mg once daily. (2.2) ● Nucleoside-inhibitor-treatment-naïve and lamivudine-experienced pediatric patients at least 2 years of age and weighing at least 10 kg: dosing is based on weight. (2.3) ● Lamivudine-refractory or known lamivudine or telbivudine resistance substitutions (greater than or equal to 16 years old): 1 mg once daily.
(2.2) ● Decompensated liver disease (adults): 1 mg once daily. (2.2) ● Renal impairment: Dosage adjustment is recommended if creatinine clearance is less than 50 mL/min. (2.4) ● Entecavir tablets should be administered on an empty stomach.
(2.1)
2.1Timing of Administration Entecavir tablets should be administered on an empty stomach (at least 2 hours after a meal and 2 hours before the next meal).
2.2Recommended Dosage in Adults Compensated Liver Disease The recommended dose of entecavir tablets for chronic hepatitis B virus infection in nucleoside-inhibitor-treatment-naïve adults and adolescents 16 years of age and older is 0.5 mg once daily. The recommended dose of entecavir tablets in adults and adolescents (at least 16 years of age) with a history of hepatitis B viremia while receiving lamivudine or known lamivudine or telbivudine resistance substitutions rtM204I/V with or without rtL180M, rtL80I/V, or rtV173L is 1 mg once daily.
Decompensated Liver Disease The recommended dose of entecavir tablets for chronic hepatitis B virus infection in adults with decompensated liver disease is 1 mg once daily.
2.3Recommended Dosage in Pediatric Patients Table 1 describes the recommended dose of entecavir for pediatric patients 2 years of age or older and weighing at least 10 kg. The oral solution should be used for patients with body weight up to 30 kg. Table 1: Dosing Schedule for Peditric Patients Recommended Once-Daily Dose of Oral Solution (mL) Body Weight (kg) Treatment Naive Patients a Lamuvidine-Experienced Patients b 10 o 11 3 6 greater than 11 to 14 4 8 greater than 14 to 17 5 10 greater than 17 to 20 6 12 greater than 20 to 23 7 14 greater than 23 to 26 8 16 greater than 26 to 30 9 18 greater than 30 10 20 a Children with body weight greater than 30 kg should receive 10 mL (0.5 mg) of oral solution or one 0.5 mg tablet once daily. b Children with body weight greater than 30 kg should receive 20 mL (1 mg) of oral solution or one 1 mg tablet once daily.
2.4Renal Impairment In adult subjects with renal impairment, the apparent oral clearance of entecavir decreased as creatinine clearance decreased [see Clinical Pharmacology (12.3)]. Dosage adjustment is recommended for patients with creatinine clearance less than 50 mL/min, including patients on hemodialysis or continuous ambulatory peritoneal dialysis (CAPD), as shown in Table 2. The once-daily dosing regimens are preferred.
Table 2: Recommended Dosage of Entecavir Tablets in Adult Patients with Renal Impairment Creatinine Clearance (mL/min) Usual Dose (0.5 mg) Lamividune-Refractory or Decompensated Liver Disease (1 mg) 50 or greater 0.5 mg once daily 1 mg once daily 30 to less than 50 0.25 mg once dailya OR 0.5 mg every 48 hours 0.5 mg once daily OR 1 mg every 48 hours 10 to less than 30 0.15 mg once dailya OR 0.5 mg every 72 hours 0.3 mg once dailya OR 1 mg every 72 hours Less than 10 Hemodialysisb or CAPD 0.05 mg once dailya OR 0.5 mg every 7 days 0.1 mg once dailya OR 1 mg every 7 day a For doses less than 0.5 mg, entecavir oral solution is recommended. b If administered on a hemodialysis day, administer entecavir tablets after the hemodialysis session.
Although there are insufficient data to recommend a specific dose adjustment of entecavir in pediatric patients with renal impairment, a reduction in the dose or an increase in t… [Excerpted — this section continues on DailyMed.]
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS ● Entecavir Tablets, 0.5 mg are white to off-white, triangular-shaped film-coated tablets, debossed with “YSP” on one side and “222” on the other side. ● Entecavir Tablets, 1 mg are pink, triangular-shaped film-coated tablets, debossed with “YSP” on one side and “216” on the other side. ● Tablets: 0.5 mg and 1 mg (3, 16)
⛔ Contraindications ▾
4 CONTRAINDICATIONS None. ● None. (4)
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS ● Severe acute exacerbations of hepatitis B virus infection after discontinuation: Monitor hepatic function closely for at least several months. (5.1, 6.1) ● Co-infection with HIV: Entecavir is not recommended unless the patient is also receiving HAART. (5.2) ● Lactic acidosis and severe hepatomegaly with steatosis: If suspected, treatment should be suspended. (5.3)
5.1Severe Acute Exacerbations of Hepatitis B Severe acute exacerbations of hepatitis B have been reported in patients who have discontinued anti-hepatitis B therapy, including entecavir [see Adverse Reactions (6.1)]. 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.
5.2Patients Co-infected with HIV and HBV Entecavir has not been evaluated in HIV/HBV co-infected patients who were not simultaneously receiving effective HIV treatment. Limited clinical experience suggests there is a potential for the development of resistance to HIV nucleoside reverse transcriptase inhibitors if entecavir is used to treat chronic hepatitis B virus infection in patients with HIV infection that is not being treated [see Microbiology (12.4)]. Therefore, therapy with entecavir is not recommended for HIV/HBV co-infected patients who are not also receiving HAART.
Before initiating entecavir therapy, HIV antibody testing should be offered to all patients. Entecavir has not been studied as a treatment for HIV infection and is not recommended for this use.
5.3Lactic Acidosis and Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogue inhibitors, including entecavir, alone or in combination with antiretrovirals. A majority of these cases have been in women. Obesity and prolonged nucleoside inhibitor exposure may be risk factors.
Particular caution should be exercised when administering nucleoside analogue inhibitors to any patient with known risk factors for liver disease; however, cases have also been reported in patients with no known risk factors. Lactic acidosis with entecavir use has been reported, often in association with hepatic decompensation, other serious medical conditions, or drug exposures. Patients with decompensated liver disease may be at higher risk for lactic acidosis.
Treatment with entecavir should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS The following adverse reactions are discussed in other sections of the labeling: ● Exacerbations of hepatitis after discontinuation of treatment [see Boxed Warning, Warnings and Precautions (5.1)]. ● Lactic acidosis and severe hepatomegaly with steatosis [see Boxed Warning, Warnings and Precautions (5.3)]. ● In adults, the most common adverse reactions (≥3%, all severity grades) are headache, fatigue, dizziness, and nausea. The adverse reactions observed in pediatric patients were consistent with those observed in adults.
(6.1) To report SUSPECTED ADVERSE REACTIONS, contact Carlsbad Technology, Inc. at 1-760-431-8284 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
6.1Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Clinical Trial Experience in Adults Compensated Liver Disease Assessment of adverse reactions is based on four studies (AI463014, AI463022, AI463026, and AI463027) in which 1720 subjects with chronic hepatitis B virus infection and compensated liver disease received double-blind treatment with entecavir 0.5 mg/day (n=679), entecavir 1 mg/day (n=183), or lamivudine (n=858) for up to 2 years.
Median duration of therapy was 69 weeks for entecavir-treated subjects and 63 weeks for lamivudine-treated subjects in Studies AI463022 and AI463027 and 73 weeks for entecavir-treated subjects and 51 weeks for lamivudine-treated subjects in Studies AI463026 and AI463014. The safety profiles of entecavir and lamivudine were comparable in these studies. The most common adverse reactions of any severity (≥3%) with at least a possible relation to study drug for entecavir-treated subjects were headache, fatigue, dizziness, and nausea.
The most common adverse reactions among lamivudine-treated subjects were headache, fatigue, and dizziness. One percent of entecavir-treated subjects in these four studies compared with 4% of lamivudine treated subjects discontinued for adverse events or abnormal laboratory test results. Clinical adverse reactions of moderate-severe intensity and considered at least possibly related to treatment occurring during therapy in four clinical studies in which entecavir was compared with lamivudine are presented in Table 3. a Includes events of possible, probable, certain, or unknown relationship to treatment regimen. b Studies AI463022 and AI463027. c Includes Study AI463026 and the entecavir 1 mg and lamivudine treatment arms of Study AI463014, a Phase 2 multinational, randomized, double-blind study of three doses of entecavir (0.1, 0.5, and 1 mg) once daily versus continued lamivudine 100 mg once daily for up to 52 weeks in subjects who experienced recurrent viremia on lamivudine therapy.
Laboratory Abnormalities Frequencies of selected treatment-emergent laboratory abnormalities reported during therapy in four clinical trials of entecavir compared with lamivudine are listed in Table 4. a On-treatment value worsened from baseline to Grade 3 or Grade 4 for all parameters except albumin (any on-treatment value <2.5 g/dL), confirmed creatinine increase ≥0.5 mg/dL, and ALT >10 × ULN and >2 × baseline. b Studies AI463022 and AI463027. c Includes Study AI463026 and the entecavir 1 mg and lamivudine treatment arms of Study AI463014, a Phase 2 multinational, randomized, double-blind study of three doses of entecavir (0.1, 0.5, and 1 mg) once daily versus continued lamivudine 100 mg once daily for up to 52 weeks in subjects who experienced recurrent viremia on lamivudine therapy. d Includes hematology, routine chemistries, renal and liver function tests, pancreatic enzymes, and urinalysis. e Grade 3 = 3+, large, ≥500 mg/dL; Grade 4 = 4+, marked, severe. f Grade 3 = 3+, large; Grade 4 = ≥4+, marked, severe, many.
ULN=upper limit of normal. Among entecavir-treat… [Excerpted — this section continues on DailyMed.]
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS Since entecavir is primarily eliminated by the kidneys [see Clinical Pharmacology (12.3)], coadministration of entecavir with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of either entecavir or the coadministered drug. Coadministration of entecavir with lamivudine, adefovir dipivoxil, or tenofovir disoproxil fumarate did not result in significant drug interactions. The effects of coadministration of entecavir with other drugs that are renally eliminated or are known to affect renal function have not been evaluated, and patients should be monitored closely for adverse events when entecavir is coadministered with such drugs.
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS ● Liver transplant recipients: Limited data on safety and efficacy are available. (8.8) See 17 for PATIENT COUNSELING INFORMATION and FDA- approved patient labeling
8.1Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to entecavir during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Prospective pregnancy data from the APR are not sufficient to adequately assess the risk of birth defects, miscarriage or adverse maternal or fetal outcomes.
Entecavir use during pregnancy has been evaluated in a limited number of individuals reported to the APR and the number of exposures to entecavir is insufficient to make a risk assessment compared to a reference population. The estimated background rate for major birth defects is 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP). The rate of miscarriage is not reported in the APR.
All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of miscarriage in clinically recognized pregnancies is 15–20%. In animal reproduction studies, no adverse developmental effects were observed with entecavir at clinically relevant exposures.
No developmental toxicities were observed at systemic exposures (AUC) approximately 25 (rats) and 200 (rabbits) times the exposure at the maximum recommended human dose (MRHD) of 1 mg/day (see Data). Data Animal Data Entecavir was administered orally to pregnant rats (at 2, 20, and 200 mg per kg per day) and rabbits (at 1, 4, and 16 mg per kg per day) during organogenesis (on gestation Days 6 through 15 [rat] and 6 through 18 [rabbit]). In rats, embryofetal toxicity including postimplantation loss, resorptions, tail and vertebral malformations, skeletal variations including reduced ossification (vertebrate, sternebrae, and phalanges) and extra lumbar vertebrae and ribs, and lower fetal body weights were observed at systemic exposures (AUC) 3,100 times those in humans at the MRHD.
Maternal toxicity was also observed at this dose level. In rabbits, embryofetal toxicity including post-implantation loss, resorptions and skeletal variations, including reduced ossification (hyoid) and increased incidence of 13th rib, were observed at systemic exposures (AUC) 883 times those in humans at the MRHD. There were no signs of embryofetal toxicity when pregnant animals received oral entecavir at 28 (rat) and 212 (rabbit) times the human exposure (AUC) at the MRHD.
In a pre/postnatal development study, entecavir was administered orally to pregnant rats at 0.3, 3, and 30 mg per kg per day from gestation day 6 to lactation/post-partum day 20. No adverse effects on the offspring occurred at up to the highest dose evaluated, resulting in exposures (AUC) greater than 94 times those in humans at the MRHD.
8.2Lactation Risk Summary It is not known whether entecavir is present in human breast milk, affects human milk production, or has effects on the breastfed infant. When administered to lactating rats, entecavir was present in milk (see Data). The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for entecavir and any potential adverse effects on the breastfed infant from entecavir or from the underlying maternal condition.
Data Entecavir was excreted into the milk of lactating rats following a single oral dose of 10 mg per kg on lactation day 7. Entecavir in milk was approximately 25% that in maternal plasma (based on AUC).
8.4Pediatric Use Entecavir was evaluated in two clinical trials of pediatric subjects 2 years of age and older with HBeAg-positive chronic HBV infection and compensated liver disease. The exposure of entecavir in nucleoside-inhibitor-treatment-naïve and lami… [Excerpted — this section continues on DailyMed.]
🆘 Overdosage ▾
10 OVERDOSAGE There is limited experience of entecavir overdosage reported in patients. Healthy subjects who received single entecavir doses up to 40 mg or multiple doses up to 20 mg/day for up to 14 days had no increase in or unexpected adverse events. If overdose occurs, the patient must be monitored for evidence of toxicity, and standard supportive treatment applied as necessary.
Following a single 1 mg dose of entecavir, a 4-hour hemodialysis session removed approximately 13% of the entecavir dose.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism of Action Entecavir is an antiviral drug against hepatitis B virus [see Micribiology (12.4) ].
12.3Pharmacokinetics The single- and multiple-dose pharmacokinetics of entecavir were evaluated in healthy subjects and subjects with chronic hepatitis B virus infection. Absorption Following oral administration in healthy subjects, entecavir peak plasma concentrations occurred between 0.5 and 1.5 hours. Following multiple daily doses ranging from 0.1 to 1 mg, C max and area under the concentration-time curve (AUC) at steady state increased in proportion to dose.
Steady state was achieved after 6 to 10 days of once-daily administration with approximately 2-fold accumulation. For a 0.5 mg oral dose, Cmax at steady state was 4.2 ng/mL and trough plasma concentration (C trough ) was 0.3 ng/mL. For a 1 mg oral dose, Cmax was 8.2 ng/mL and C trough was 0.5 ng/mL.
In healthy subjects, the bioavailability of the tablet was 100% relative to the oral solution. The oral solution and tablet may be used interchangeably. Effects of food on oral absorption : Oral administration of 0.5 mg of entecavir with a standard high-fat meal (945 kcal, 54.6 g fat) or a light meal (379 kcal, 8.2 g fat) resulted in a delay in absorption (1–1.5 hours fed vs.
0.75hours fasted), a decrease in Cmax of 44%–46%, and a decrease in AUC of 18%–20% [see Dosage and Administration (2) ]. Distribution Based on the pharmacokinetic profile of entecavir after oral dosing, the estimated apparent volume of distribution is in excess of total body water, suggesting that entecavir is extensively distributed into tissues. Binding of entecavir to human serum proteins in vitro was approximately 13%.
Metabolism and Elimination Following administration of 14C-entecavir in humans and rats, no oxidative or acetylated metabolites were observed. Minor amounts of phase II metabolites (glucuronide and sulfate conjugates) were observed. Entecavir is not a substrate, inhibitor, or inducer of the cytochrome P450 (CYP450) enzyme system.
See Drug Interactions, below. After reaching peak concentration, entecavir plasma concentrations decreased in a bi-exponential manner with a terminal elimination half-life of approximately 128–149 hours. The observed drug accumulation index is approximately 2-fold with once-daily dosing, suggesting an effective accumulation half-life of approximately 24 hours.
Entecavir is predominantly eliminated by the kidney with urinary recovery of unchanged drug at steady state ranging from 62% to 73% of the administered dose. Renal clearance is independent of dose and ranges from 360 to 471 mL/min suggesting that entecavir undergoes both glomerular filtration and net tubular secretion [see Drug Interactions (7) ]. Special Populations Gender: There are no significant gender differences in entecavir pharmacokinetics.
Race: There are no significant racial differences in entecavir pharmacokinetics. Elderly: The effect of age on the pharmacokinetics of entecavir was evaluated following administration of a single 1 mg oral dose in healthy young and elderly volunteers. Entecavir AUC was 29.3% greater in elderly subjects compared to young subjects.
The disparity in exposure between elderly and young subjects was most likely attributable to differences in renal function. Dosage adjustment of entecavir should be based on the renal function of the patient, rather than age [see Dosage and Administration (2.4) ]. Pediatrics: The steady-state pharmacokinetics of entecavir were evaluated in nucleosideinhibitor-naïve and lamivudine-experienced HBeAg-positive pediatric subjects 2 to less than 18 years of age with compensated liver disease.
Results are shown in Table 7. Entecavirexposure among nucleoside-inhibitor-naïve subjects was similar to the exposure achieved in adults receiving once-daily doses of 0.5 mg. Entecavir exposure among lamivudine- experienced subjects was similar to the exposure achieved in adults receiving once-daily doses of 1 mg.… [Excerpted — this section continues on DailyMed.]
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING Entecavir Tablets are available in the following strengths and configurations of plastic bottles with child-resistant closures: Product Strength and Dosage Form Description Quantity NDC Number Entecavir Tablets, 0.5 mg A white to off-white, triangular-shaped film-coated tablet, debossed with “YSP” on one side and “222” on the other side. 30 tablets 51407-589-30 Storage Entecavir Tablets should be stored in a tightly closed container at 25° C (77° F); excursions permitted between 15–30° C (59–86° F) [see USP Controlled Room Temperature].
Protect from light.
📋 Description ▾
11 DESCRIPTION Entecavir Tablets is a guanosine nucleoside analogue with selective activity against HBV. The chemical name for entecavir is 2-amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)- 2-methylenecyclopentyl]-6H-purin-6-one, monohydrate. Its molecular formula is C 12 H 15 N 5 O 3 •H 2 O, which corresponds to a molecular weight of 295.3.
Entecavir has the following structural formula: Entecavir is a white to off-white powder. It is slightly soluble in water (2.4 mg/mL), and the pH of the saturated solution in water is 7.9 at 25°C±0.5°C. Entecavir film-coated tablets are available for oral administration in strengths of 0.5 mg and 1 mg of entecavir.
Entecavir 0.5 mg and 1 mg film-coated tablets contain the following inactive ingredients: lactose monohydrate, microcrytalline cellulose, crospovidone, providone, and magnesium stereate. The tablet coating contains titanium dioxide, hypromellose, polyethylene glycol 400, and iron oxide red (1 mg tablet only). Meet USP Dissolution Test 2.
Structural Formula
💬 Medication Guide ▾
Patient Information Entecavir (en-TEK-a-vir) Tablets Read this Patient Information before you start taking entecavir tablets and each time you get a refill. There may be new information. This information does not take the place of talking with your healthcare provider about your medical condition or treatment.
What is the most important information I should know about entecavir tablets? 1. Your hepatitis B virus (HBV) infection may get worse if you stop taking entecavir tablets.
This usually happens within 6 months after stopping entecavir tablets. ● Take entecavir tablets exactly as prescribed. ● Do not run out of entecavir tablets. ● 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 tablets. 2. If you have or get HIV that is not being treated with medicines while taking entecavir tablets, 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 tablets and anytime after that when there is a chance you were exposed to HIV. Entecavir tablets can cause serious side effects including: 3. Lactic acidosis (buildup of acid in the blood).
Some people who have taken entecavir tablets or medicines like entecavir tablets (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 tablets 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.
4. Serious liver problems. Some people who have taken medicines like entecavir tablets 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 tablets, for a long time.
What are entecavir tablets? Entecavir tablets are a prescription medicine used to treat chronic hepatitis B virus (HBV) in adults and children 2 years of age and older who have active liver disease. ● Entecavir tablets will not cure HBV. ● Entecavir tablets may lower the amount of HBV in the body. ● Entecavir tablets may lower the ability of HBV to multiply and infect new liver cells. ● Entecavir tablets may improve the condition of your liver. ● It is not known whether entecavir tablets will reduce your chances of getting liver cancer or liver damage (cirrhosis), which may be caused by chronic HBV infection. ● It is not known if entecavir tablets are safe and effective for use in children less than 2 years of age.
What should I tell my healthcare provider before taking entecavir tablets? Before you take entecavir tablets, tell your healthcare provider if you: ● have kidney problems. Your entecavir tablets dose or schedule may need to be changed. ● have received medicine… [Excerpted — this section continues on DailyMed.]
🔬 Clinical Studies ▾
14 CLINICAL STUDIES
14.1Outcomes in Adults At 48 Weeks The safety and efficacy of entecavir in adults were evaluated in three Phase 3 active-controlled trials. These studies included 1633 subjects 16 years of age or older with chronic hepatitis B virus infection (serum HBsAg-positive for at least 6 months) accompanied by evidence of viral replication (detectable serum HBV DNA, as measured by the bDNA hybridization or PCR assay). Subjects had persistently elevated ALT levels at least 1.3 times ULN and chronic inflammation on liver biopsy compatible with a diagnosis of chronic viral hepatitis.
The safety and efficacy of entecavir were also evaluated in a study of 191 HBV- infected subjects with decompensated liver disease and in a study of 68 subjects co-infected with HBV and HIV. Nucleoside-inhibitor-naïve Subjects with Compensated Liver Disease HBeAg-positive: Study AI463022 was a multinational, randomized, double-blind study of entecavir 0.5 mg once daily versus lamivudine 100 mg once daily for a minimum of 52 weeks in 709 (of 715 randomized) nucleoside-inhibitor-naïve subjects with chronic hepatitis B virus infection, compensated liver disease, and detectable HBeAg.
The mean age of subjects was 35 years, 75% were male, 57% were Asian, 40% were Caucasian, and 13% had previously received interferon-α. At baseline, subjects had a mean Knodell Necroinflammatory Score of 7.8, mean serum HBV DNA as measured by Roche COBAS Amplicor® PCR assay was 9.66 log10 copies/mL, and mean serum ALT level was 143 U/L. Paired, adequate liver biopsy samples were available for 89% of subjects.
HBeAg-negative (anti-HBe-positive/HBV DNA-positive): Study AI463027 was a multinational, randomized, double-blind study of entecavir 0.5 mg once daily versus lamivudine 100 mg once daily for a minimum of 52 weeks in 638 (of 648 randomized) nucleoside-inhibitor-naïve subjects with HBeAg-negative (HBeAb-positive) chronic hepatitis B virus infection and compensated liver disease. The mean age of subjects was 44 years, 76% were male, 39% were Asian, 58% were Caucasian, and 13% had previously received interferon-α. At baseline, subjects had a mean Knodell Necroinflammatory Score of 7.8, mean serum HBV DNA as measured by Roche COBAS Amplicor PCR assay was 7.58 log10 copies/mL, and mean serum ALT level was 142 U/L.
Paired, adequate liver biopsy samples were available for 88% of subjects. In Studies AI463022 and AI463027, entecavir was superior to lamivudine on the primary efficacy endpoint of Histologic Improvement, defined as a 2-point or greater reduction in Knodell Necroinflammatory Score with no worsening in Knodell Fibrosis Score at Week 48, and on the secondary efficacy measures of reduction in viral load and ALT normalization. Histologic Improvement and change in Ishak Fibrosis Score are shown in Table 9.
Selected virologic, biochemical, and serologic outcome measures are shown in Table 10. a Subjects with evaluable baseline histology (baseline Knodell Necroinflammatory Score ≥2). b ≥2-point decrease in Knodell Necroinflammatory Score from baseline with no worsening of the Knodell Fibrosis Score. c For Ishak Fibrosis Score, improvement = ≥1-point decrease from baseline and worsening = ≥1-point increase from baseline. a Roche COBAS Amplicor PCR assay [lower limit of quantification (LLOQ) = 300 copies/mL]. Histologic Improvement was independent of baseline levels of HBV DNA or ALT.
Lamivudine-refractory Subjects with Compensated Liver Disease Study AI463026 was a multinational, randomized, double-blind study of entecavir in 286 (of 293 randomized) subjects with lamivudine-refractory chronic hepatitis B virus infection and compensated liver disease. Subjects receiving lamivudine at study entry either switched to entecavir 1 mg once daily (with neither a washout nor an overlap period) or continued on lamivudine 100 mg for a minimum of 52 weeks. The mean age of subjects was 39 years, 76% were male, 37% were Asian, 62% were Caucasian, and 52% had previously recei… [Excerpted — this section continues on DailyMed.]
🧪 Nonclinical Toxicology ▾
13 NONCLINICAL TOXICOLOGY
13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term oral carcinogenicity studies of entecavir in mice and rats were carried out at exposures up to approximately 42 times (mice) and 35 times (rats) those observed in humans at the highest recommended dose of 1 mg/day. In mouse and rat studies, entecavir was positive for carcinogenic findings. It is not known how predictive the results of rodent carcinogenicity studies may be for humans [see Adverse Reactions (6.2) ].
In mice, lung adenomas were increased in males and females at exposures 3 and 40 times those in humans. Lung carcinomas in both male and female mice were increased at exposures 40 times those in humans. Combined lung adenomas and carcinomas were increased in male mice at exposures 3 times and in female mice at exposures 40 times those in humans.
Tumor development was preceded by pneumocyte proliferation in the lung, which was not observed in rats, dogs, or monkeys administered entecavir, supporting the conclusion that lung tumors in mice may be a species-specific event. Hepatocellular carcinomas were increased in males and combined liver adenomas and carcinomas were also increased at exposures 42 times those in humans. Vascular tumors in female mice (hemangiomas of ovaries and uterus and hemangiosarcomas of spleen) were increased at exposures 40 times those in humans.
In rats, hepatocellular adenomas were increased in females at exposures 24 times those in humans; combined adenomas and carcinomas were also increased in females at exposures 24 times those in humans. Brain gliomas were induced in both males and females at exposures 35 and 24 times those in humans. Skin fibromas were induced in females at exposures 4 times those in humans.
Mutagenesis Entecavir was clastogenic to human lymphocyte cultures. Entecavir was not mutagenic in the Ames bacterial reverse mutation assay using S. typhimurium and E. coli strains in the presence or absence of metabolic activation, a mammalian-cell gene mutation assay, and a transformation assay with Syrian hamster embryo cells. Entecavir was also negative in an oral micronucleus study and an oral DNA repair study in rats.
Impairment of Fertility In reproductive toxicology studies, in which animals were administered entecavir at up to 30 mg/kg for up to 4 weeks, no evidence of impaired fertility was seen in male or female rats at systemic exposures greater than 90 times those achieved in humans at the highest recommended dose of 1 mg/day. In rodent and dog toxicology studies, seminiferous tubular degeneration was observed at exposures 35 times or greater than those achieved in humans. No testicular changes were evident in monkeys.
13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term oral carcinogenicity studies of entecavir in mice and rats were carried out at exposures up to approximately 42 times (mice) and 35 times (rats) those observed in humans at the highest recommended dose of 1 mg/day. In mouse and rat studies, entecavir was positive for carcinogenic findings. It is not known how predictive the results of rodent carcinogenicity studies may be for humans [see Adverse Reactions (6.2) ].
In mice, lung adenomas were increased in males and females at exposures 3 and 40 times those in humans. Lung carcinomas in both male and female mice were increased at exposures 40 times those in humans. Combined lung adenomas and carcinomas were increased in male mice at exposures 3 times and in female mice at exposures 40 times those in humans.
Tumor development was preceded by pneumocyte proliferation in the lung, which was not observed in rats, dogs, or monkeys administered entecavir, supporting the conclusion that lung tumors in mice may be a species-specific event. Hepatocellular carcinomas were increased in males and combined liver adenomas and carcinomas were also increased at exposures 42 times those in humans. Vascular tumors in female mice (hemang… [Excerpted — this section continues on DailyMed.]
📄 Package Label / Principal Display Panel ▾
Package Label Entecavir Tablets 0.5 mg 30 ct NDC 51407-589-30 Entecavir Tablets 0.5 mg 30 count 51407-589-30OL.jpg
Medicare Part D spend CMS · PART D · 2026 (Q1)
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