Comprehensive medication guide to Entecavir including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$10–$60 copay for commercial insurance (Tier 2–3 on most formularies); Medicare Part D typically places entecavir on Tier 4, with copays ranging from $15 to $836 depending on plan and benefit phase. Prior authorization may apply.
Estimated Cash Pricing
$11–$31 for a 30-day supply of generic entecavir 0.5 mg with a GoodRx or SingleCare discount card; retail price without any coupon is approximately $1,126 per 30-tablet supply.
Medfinder Findability Score
80/100
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Entecavir (brand name Baraclude) is an antiviral medication used to treat chronic hepatitis B virus (HBV) infection in adults and children aged 2 years and older who weigh at least 10 kilograms (22 pounds). It belongs to the nucleoside reverse transcriptase inhibitor (NRTI) drug class—specifically, it is a deoxyguanosine analogue that blocks HBV replication.
Entecavir was FDA-approved in March 2005. Bristol-Myers Squibb originally marketed it as Baraclude, but the patent has expired and generic entecavir is now widely available from multiple manufacturers. It is on the World Health Organization's List of Essential Medicines, reflecting its critical role in global hepatitis B management.
Entecavir is available as 0.5 mg tablets, 1 mg tablets, and a 0.05 mg/mL oral solution. It does not cure hepatitis B, but suppresses viral replication to protect the liver from ongoing damage and reduce the long-term risks of cirrhosis and liver cancer.
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Entecavir is a deoxyguanosine analogue that closely resembles a natural DNA building block. Inside liver cells, it is converted to its active form—entecavir triphosphate—which competes with the natural building block (deoxyguanosine triphosphate) for the hepatitis B virus's reverse transcriptase enzyme.
When entecavir triphosphate is incorporated into the viral DNA chain instead of the natural building block, it halts DNA synthesis. Uniquely, entecavir blocks all three critical steps of HBV reverse transcriptase activity: base priming, reverse transcription of negative-strand DNA, and positive-strand DNA synthesis. This triple blockade makes it highly potent—68–90% of patients achieve undetectable HBV DNA levels after 48 weeks of therapy.
Entecavir is not a substrate, inhibitor, or inducer of the CYP450 enzyme system, which means it avoids most common drug-drug interactions. It is primarily eliminated by the kidneys (62–73% of the dose excreted unchanged), which is why dose adjustments are needed in patients with reduced kidney function.
0.5 mg — film-coated tablet
Standard dose for treatment-naive adults and adolescents ≥16 years
1 mg — film-coated tablet
For lamivudine-resistant patients or decompensated liver disease
0.05 mg/mL — oral solution
For children ≥2 years/≥10 kg or adults unable to swallow tablets; weight-based dosing
Entecavir is not on the FDA's official drug shortage list as of 2026, and multiple generic manufacturers produce it. However, localized pharmacy stockouts are reported by patients, primarily because entecavir treats a relatively small patient population and many retail pharmacies stock limited quantities. The oral solution (0.05 mg/mL) is particularly hard to find at standard retail locations.
Specialty pharmacies (CVS Specialty, Walgreens Specialty, Accredo, Diplomat) typically have more reliable supply than standard retail chains. Mail-order pharmacies affiliated with insurance plans also tend to carry it consistently. Patients in rural areas or those needing the 1 mg strength or oral solution may face more frequent access challenges.
To find which pharmacies near you have entecavir in stock without calling each one yourself, use medfinder. medfinder calls pharmacies on your behalf and texts you with results.
Entecavir is not a controlled substance, so any licensed prescriber with authority to write prescriptions in their state can prescribe it—no DEA registration or special licensing is required beyond standard prescribing authority. Common prescriber types include:
Telehealth prescribing is available for established patients already on entecavir with stable lab values. New hepatitis B diagnoses typically require in-person evaluation and lab testing (HBV DNA quantification, HBeAg status, liver enzymes) before entecavir is initiated.
No. Entecavir is not a controlled substance and is not scheduled by the DEA. There are no special prescribing restrictions, no requirement for DEA-registered prescribers specifically, and no limits on the number of refills. Any licensed prescriber—including physicians, nurse practitioners, and physician assistants with prescribing authority—can prescribe entecavir.
Patients do not need to pick up entecavir in person—mail-order pharmacy fills for 90-day supplies are available and are one of the best ways to maintain a consistent supply for this lifelong treatment. Prescriptions can be transferred between pharmacies without restrictions beyond standard pharmacy law in your state.
Most patients tolerate entecavir well. In clinical trials, the most common side effects reported were:
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Tenofovir disoproxil fumarate (TDF, Viread)
Co-first-line NRTI for HBV; preferred in pregnancy and HIV/HBV co-infection; associated with higher bone density loss and kidney effects than entecavir
Tenofovir alafenamide (TAF, Vemlidy)
Newer formulation with improved renal and bone safety vs. TDF; preferred for patients with CKD or osteoporosis; still brand-name as of 2026
Lamivudine (3TC, Epivir-HBV)
Older NRTI; lower potency and ~70% resistance rate at 5 years; rarely first-line; may be used as short-term bridge only
Pegylated interferon alfa-2a (Pegasys)
Injectable immunomodulator; finite 48-week course; can lead to lasting immune control in some patients; more side effects; contraindicated in decompensated cirrhosis
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HIV antiretrovirals (unrecognized HIV)
majorEntecavir has weak anti-HIV activity; use in untreated HIV/HBV co-infection can select for HIV NRTI resistance mutations
Metformin
moderateBoth use active tubular secretion for renal elimination; potential for increased levels of both drugs and additive lactic acidosis risk
Tenofovir disoproxil fumarate
moderateTDF reduces renal clearance of entecavir, potentially increasing entecavir blood levels; monitor for toxicity
Cyclosporine / tacrolimus
moderateImmunosuppressants affect renal function, altering entecavir clearance; approximately 2-fold higher entecavir exposure in transplant patients; monitor closely
Aminoglycoside antibiotics
moderateCompete for active tubular secretion; may increase entecavir concentrations and nephrotoxicity risk
NSAIDs (ibuprofen, naproxen)
minorRegular NSAID use can reduce kidney function, increasing entecavir exposure; discuss with prescriber if using NSAIDs regularly
Entecavir is one of the most effective and well-tolerated treatments available for chronic hepatitis B, with a high potency, a strong resistance barrier, and decades of clinical data supporting its safety. With generic versions available since around 2015, it is also among the most cost-accessible hepatitis B treatments when discount cards like GoodRx or SingleCare are used—with prices as low as $11–$31 per 30-day supply.
The biggest challenge many patients face is not affordability but access—finding a pharmacy near them that has entecavir in stock when they need a refill. Because hepatitis B affects a relatively small patient population, many retail pharmacies stock limited quantities. Planning refills 7–10 days early, using mail-order pharmacies, and having a backup pharmacy contact on hand are the most reliable strategies.
If you're having trouble locating entecavir at your pharmacy, medfinder can help. medfinder calls pharmacies near you to check real-time availability and texts you with results—so you can find your medication without hours of phone calls.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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