Epivir HBV (lamivudine) is a prescription antiviral medication specifically indicated for the treatment of chronic hepatitis B virus (HBV) infection in adults and pediatric patients. As a nucleoside analog reverse transcriptase inhibitor, it works by inhibiting viral DNA replication, thereby reducing viral load and liver inflammation. This oral solution and tablet formulation is designed for long-term management, aiming to suppress HBV replication, improve liver histology, and reduce the risk of cirrhosis and hepatocellular carcinoma. Clinical studies demonstrate its efficacy in achieving undetectable HBV DNA levels and hepatitis B e antigen (HBeAg) seroconversion in a significant proportion of treated patients.

Features

• Contains lamivudine as the active pharmaceutical ingredient
• Available in 100 mg scored tablets and 5 mg/mL oral solution
• Specifically formulated and dosed for hepatitis B virus (not HIV) treatment
• Manufactured under current Good Manufacturing Practice (cGMP) standards
• Bioequivalent to the reference listed drug
• Stable at room temperature with a prolonged shelf life

Benefits

• Significant viral suppression: Reduces HBV DNA to undetectable levels in many patients
• Improved liver enzymes: Normalizes ALT levels, indicating reduced hepatic inflammation
• Histological improvement: Demonstrates reduced necroinflammatory activity and fibrosis on liver biopsy
• Seroconversion potential: Facilitates HBeAg seroconversion to anti-HBe antibodies
• Convenient dosing: Once-daily regimen enhances adherence to long-term therapy
• Pediatric formulation: Oral solution allows for accurate dosing in children

Common use

Epivir HBV is indicated for the treatment of chronic hepatitis B virus infection associated with evidence of hepatitis B viral replication and active liver inflammation. It is prescribed for both HBeAg-positive and HBeAg-negative patients with compensated liver disease. The medication is typically used as monotherapy but may be part of combination regimens in certain clinical scenarios. Treatment duration is often prolonged, frequently extending beyond one year, with decisions regarding continuation based on virological response, serological status, and liver histology.

Dosage and direction

The recommended oral dosage of Epivir HBV for adults is 100 mg once daily, without regard to meals. For pediatric patients aged 2-17 years, the recommended dose is 3 mg per kg once daily, up to a maximum of 100 mg daily. The oral solution (5 mg/mL) should be administered using the provided dosing syringe for accurate measurement. Dosage adjustment is required in patients with renal impairment: for creatinine clearance 30-49 mL/min, administer 100 mg first dose then 50 mg daily; for 15-29 mL/min, 100 mg first dose then 25 mg daily; for 5-14 mL/min, 35 mg first dose then 15 mg daily; for <5 mL/min, 35 mg first dose then 10 mg daily.

Precautions

Regular monitoring of HBV DNA levels, liver function tests, and virological markers is essential throughout treatment. Patients should be advised that discontinuation of therapy may result in severe acute exacerbations of hepatitis B. Use with caution in patients with known risk factors for liver disease. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with nucleoside analogs. Patients with known risk factors for liver disease should be monitored closely. Pancreatitis has been reported in pediatric patients; monitor for signs and symptoms.

Contraindications

Epivir HBV is contraindicated in patients with previously demonstrated hypersensitivity to lamivudine or any component of the product. The formulation contains 100 mg of lamivudine, which is not appropriate for HIV treatment and should not be used concomitantly with Epivir-HIV or other lamivudine-containing products. Use in patients with untreated HIV co-infection is contraindicated unless combined with a complete HIV treatment regimen, due to risk of HIV resistance development.

Possible side effect

Common adverse reactions (≥10%) include headache, fatigue, dizziness, nausea, diarrhea, cough, nasal signs and symptoms, and musculoskeletal pain. Laboratory abnormalities may include elevated ALT, creatine kinase, and amylase levels. Serious adverse reactions include lactic acidosis with hepatomegaly, severe acute exacerbations of hepatitis B upon discontinuation, pancreatitis (primarily in pediatric patients), and immune reconstitution syndrome. Less frequent reactions include peripheral neuropathy, paresthesia, and rash.

Drug interaction

Lamivudine exhibits minimal metabolism and does not inhibit cytochrome P450 enzymes, resulting in limited drug interactions. However, concomitant administration with trimethoprim/sulfamethoxazole increases lamivudine exposure approximately 40%. Sorbitol-containing products may decrease lamivudine absorption; separate administration by at least 2 hours. Other nucleoside analogs may increase the risk of mitochondrial toxicity. Use with other hepatotoxic drugs may increase the risk of liver injury.

Missed dose

If a dose is missed, patients should take it as soon as they remember, unless it is almost time for the next scheduled dose. In that case, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed dose. Consistent daily administration is important for maintaining effective viral suppression and minimizing the development of resistance.

Overdose

There is limited experience with lamivudine overdose. Reported cases involved doses up to 6 grams daily without apparent toxic effects. However, higher doses may increase the risk of adverse reactions including peripheral neuropathy, pancreatitis, and hepatic steatosis. Hemodialysis removes lamivudine with an extraction coefficient of approximately 53%, and may be beneficial in overdose situations. Treatment should be supportive and include monitoring of vital signs and laboratory parameters.

Storage

Store Epivir HBV tablets at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Keep in original container with tight closure to protect from moisture. The oral solution should be stored at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Do not freeze. Keep both formulations out of reach of children. Discard any unused oral solution after the expiration date or if discolored.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Epivir HBV is available by prescription only and should be used under the supervision of a qualified healthcare provider. Patients should not initiate or discontinue therapy without consulting their physician. The full prescribing information contains complete details regarding uses, warnings, precautions, and adverse reactions.

Reviews

Clinical trials demonstrate that Epivir HBV produces virological response (undetectable HBV DNA) in approximately 40-55% of HBeAg-positive patients after one year of treatment, with HBeAg seroconversion occurring in 16-18% of patients. Histological improvement is observed in approximately 52-56% of treated patients versus 25% of placebo recipients. In HBeAg-negative patients, virological response occurs in approximately 60-70% of patients at one year. Long-term studies show maintained suppression in many patients, though resistance development increases with treatment duration, reaching approximately 70% after 4 years of therapy.