Prescription medication · Nucleoside Analog (HBV)
entecavir
Also sold as Baraclude. Entecavir treats chronic hepatitis B virus (HBV) infection.
Data updated 2026-05-15
- 11,247
- FDA reportsModerately reported
- 1
- InteractionFew interactions
- 99% less
- Generic vs brandHuge savings
- 3
- Recall records
What the data shows
entecavir (Baraclude) is a prescription Nucleoside Analog (HBV), reported less often than most tracked drugs (11,247 FDA reports), whose generic costs a fraction of the brand (about 99% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
entecavir (Baraclude) is a prescription Nucleoside Analog (HBV). Entecavir treats chronic hepatitis B virus (HBV) infection.
Entecavir is a medicine used to treat chronic hepatitis B infection. It helps to lower the amount of the virus in your body.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$44.09/unit
Generic Price
$0.29/unit
Generic Savings
99%
Generic Available
Yes (10 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: ENTECAVIR 0.5 MG TABLET
Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -7.5% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| April 17, 2024 | $0.3132/EA | - | 2 |
| December 18, 2024 | $0.2897/EA | -7.5% | 13 |
What it does
Entecavir treats chronic hepatitis B virus (HBV) infection.
Common side effects
Headache, Tiredness, Dizziness
Key warnings
Entecavir has the following warnings: * Stopping entecavir can cause a severe return of hepatitis B.
The sections below are summarized in plain English from entecavir's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Entecavir belongs to a class of drugs called nucleoside analogs. It works by blocking an enzyme that the hepatitis B virus needs to multiply. This helps to lower the amount of virus in your body and improve your liver health.
Side Effects (from patient reports)
Based on 11,247 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for entecavir, by number of reports
- Death
Death
539 reports
- Drug Resistance
Drug Resistance
401 reports
- Diarrhoea
Diarrhoea
363 reports
- Fatigue
Fatigue
353 reports
- Pyrexia
Pyrexia
348 reports
- Hepatitis B
Hepatitis B
327 reports
- Nausea
Nausea
313 reports
- Platelet Count Decreased
Platelet Count Decreased
289 reports
- Pneumonia
Pneumonia
286 reports
- Anaemia
Anaemia
229 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for entecavir each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where entecavir sits
entecavir has more FDA adverse-event reports than 42% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is entecavir; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 11,247 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
11,247
Reports Mentioning Death
1,842
16.4% of reports — not proof of cause
Hospitalization Reports
4,285
Top Indication
Hepatitis B
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DEATH | 539 |
| 4 | DRUG RESISTANCE | 401 |
| 5 | DIARRHOEA | 363 |
| 6 | FATIGUE | 353 |
| 7 | PYREXIA | 348 |
| 8 | HEPATITIS B | 327 |
| 9 | NAUSEA | 313 |
| 10 | PLATELET COUNT DECREASED | 289 |
| 11 | PNEUMONIA | 286 |
| 12 | ANAEMIA | 229 |
| 13 | RENAL IMPAIRMENT | 225 |
| 14 | HEPATIC FAILURE | 221 |
| 15 | WHITE BLOOD CELL COUNT DECREASED | 221 |
| 16 | NEUTROPENIA | 218 |
| 17 | ASTHENIA | 217 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Entecavir has the following warnings: * Stopping entecavir can cause a severe return of hepatitis B. Your liver function should be checked for several months after stopping. * If you have both HIV and hepatitis B, entecavir may make your HIV medicine less effective. Entecavir is not recommended if you have HIV and are not taking HIV medicine. * Entecavir can cause lactic acidosis (a buildup of acid in the blood) and severe liver problems. These can be fatal.
Known Drug Interactions
Co-administration of entecavir with lamivudine, adefovir dipivoxil, or tenofovir disoproxil fumarate did not result in significant drug interactions.
Mechanism: These two medications do not have a significant effect on each other when taken at the same time.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
What should I do if I feel sick while taking entecavir?
Can I take entecavir with other medications?
How long will I need to take entecavir?
Will entecavir cure my hepatitis B?
Can I drink alcohol while taking entecavir?
What tests will I need while taking entecavir?
Can I spread hepatitis B to others while taking entecavir?
Is there a generic version of entecavir available?
What do the numbers on the tablet mean?
Can children take entecavir?
What are the common side effects of entecavir?
Does entecavir interact with other medications?
What drug class is entecavir?
Is there a generic version of entecavir?
What pregnancy or breastfeeding source fields are listed for entecavir?
Has entecavir been recalled?
Active Recalls
Failed impurity/degradation specifications:Out of Specification result for an individual organic impurity
Zydus Pharmaceuticals (USA) Inc
Failed impurity/degradation specifications:Out of Specification result for an individual organic impurity
Zydus Pharmaceuticals (USA) Inc
Failed Impurity/Degradation Specifications
Zydus Pharmaceuticals (USA) Inc
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Malarone is a drug used to prevent and treat malaria.
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Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for entecavir: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 11,247.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 16.38%.
- alprazolam Δ 0.01 pts · 200,719 reports · Benzodiazepine 16.39%death share
- albendazole Δ 0.13 pts · 1,829 reports · Antiparasitic (Benzimidazole) 16.51%death share
- dexamethasone Δ 0.17 pts · 285,895 reports · Corticosteroid 16.20%death share
- piroxicam Δ 0.20 pts · 6,176 reports · Nonsteroidal Anti-Inflammatory Drug (NSAID) 16.58%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
Save on entecavir
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What the FDA Data Shows for entecavir
The FDA label for entecavir (sold under brand names such as Baraclude) classifies it as a prescription-only medication in the Nucleoside Analog (HBV) class. Entecavir treats chronic hepatitis B virus (HBV) infection. Official labeling lists 4 commonly reported side effects, including Headache, Tiredness, Dizziness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 11,247 voluntary reports. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.29 versus $44.09 for the brand - a 99% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 3 recall records on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: November 24, 2019
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages