Entecavir: uses, dosing, side effects & brands

Entecavir is a hepatitis b virus nucleoside analog reverse transcriptase inhibitor sold in the U.S. under one brand, for chronic hepatitis b. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesUpdated Jul 24, 2026How we research

Key facts

Drug class: Hepatitis B Virus Nucleoside Analog Reverse Transcriptase Inhibitor
Treats (across its forms): Chronic Hepatitis B
Available as: Solution · Tablet
Sold as: Baraclude
Prescription?: Prescription only
Generic available?: Not in our catalog
What the pharmacy pays: about $7 for a 30-count supply — not your price
Boxed warning: Boxed warning

How entecavir is dosed

From the FDA label for Baraclude (application NDA021798). Other entecavir products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

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) • BARACLUDE should be administered on an empty stomach. (2.1) 2.1 Timing of Administration BARACLUDE should be administered on an empty stomach (at least 2 hours after a meal and 2 hours before the next meal). 2.2 Recommended Dosage in Adults Compensated Liver Disease The recommended dose of BARACLUDE 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 BARACLUDE 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…

Entecavir side effects

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 Bristol-Myers Squibb at 1-800-721-5072 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical 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 BARACLUDE 0.5 mg/day (n=679), BARACLUDE 1 mg/day (n=183), or lamivudine (n=858) for up to 2 years. Median duration of therapy was 69…

Who shouldn’t take entecavir

None. • None. (4)

Entecavir drug interactions

Since entecavir is primarily eliminated by the kidneys [see Clinical Pharmacology (12.3) ] , coadministration of BARACLUDE 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 BARACLUDE 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 BARACLUDE is coadministered with such drugs. Drug Interactions The metabolism of entecavir was evaluated in in vitro and in vivo studies. Entecavir is not a substrate, inhibitor, or inducer of the cytochrome P450 (CYP450) enzyme system. At concentrations up to approximately 10,000-fold higher than those obtained in humans, entecavir inhibited none of the major human CYP450 enzymes 1A2, 2C9, 2C19, 2D6, 3A4, 2B6, and 2E1. At concentrations up to approximately 340-fold higher than those observed in humans, entecavir did not induce the human CYP450 enzymes 1A2, 2C9, 2C19, 3A4, 3A5, and 2B6. The pharmacokinetics of entecavir are unlikely to be affected by coadministration with agents that are either metabolized by, inhibit, or induce the CYP450 system. Likewise, the pharmacokinetics of known CYP substrates are unlikely to be affected by coadministration of entecavir. The steady-state pharmacokinetics of entecavir and coadministered drug were not altered in interaction studies of entecavir with lamivudine, adefovir dipivoxil, and tenofovir disoproxil fumarate [see Drug Interactions (7) ].

Every entecavir product we track (1)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Only one: Baraclude.

What entecavir pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Entecavir pill imprints
Imprint	Strength	Colour	Shape	Maker
CL;426	0.5 mg	white	triangle	—
CL;425	1 mg	pink	triangle	—
AN;446	0.5 mg	white	oval	—
AN;449	1 mg	pink	oval	—
CL;426	0.5 mg	white	triangle	—
CL;425	1 mg	pink	triangle	—
222	0.5 mg	white	triangle	—
C1	0.5 mg	white	round	—
C2	1.0 mg	pink	round	—

Entecavir recalls

From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.

How long entecavir keeps

No entecavir label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.

Does entecavir expire? The in-use limits and storage rules from its labels

Entecavir and breastfeeding

From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.

Entecavir has not been studied in nursing mothers being treated for hepatitis B infection. An alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Full LactMed record for entecavir: levels in milk, effects in breastfed infants, and the drugs it would consider instead

National Institute of Child Health and Human Development, record revised June 15, 2020. LactMed states its information is not a substitute for professional judgement.

What people report to the FDA about entecavir

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 7,409 reports naming entecavir, and the FDA flagged 88% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:

drug resistance359 reports
hepatitis b261 reports
diarrhoea259 reports
pyrexia258 reports
fatigue241 reports
platelet count decreased233 reports
pneumonia214 reports
nausea210 reports

Read these as a signal, not a rate. A report does not mean entecavir caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.

Source: openFDA drug/event (FAERS), retrieved July 25, 2026.

Related calculators

How long it stays in your system →

Frequently asked questions

What is entecavir?

BARACLUDE ® is the tradename for entecavir, a guanosine nucleoside analogue with selective activity against HBV.

What kind of drug is entecavir?

The FDA classifies entecavir as a hepatitis b virus nucleoside analog reverse transcriptase inhibitor. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take entecavir with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run entecavir against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What forms does entecavir come in?

Across the brands we track, entecavir is currently marketed as solution and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic entecavir?

We do not currently list a generic-labelled entecavir product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.

Has entecavir been recalled?

The FDA's Enforcement database lists 4 recall records whose product description mentions entecavir. The most recent: Entecavir Tablets (Sep 24, 2025). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

Cite this page

APA: pharmaranks. (2026, July 24). Entecavir: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/entecavir
MLA: “Entecavir: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/entecavir.

We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.

Read the full FDA label for entecavir on DailyMed (NIH) ↗ — including its boxed warning in full.