HEPTAVIR-100 Tablets HEPTAVIR-100 contains Lamivudine at a 100 mg dosage, specifically formulated for the treatment of chronic Hepatitis B Virus (HBV) infection with evidence of viral replication and active liver inflammation. As a synthetic nucleoside analogue of cytidine, lamivudine is phosphorylated inside host cells to its active metabolite, lamivudine 5'-triphosphate (3TC-TP). 3TC-TP inhibits HBV DNA polymerase (reverse transcriptase) both competitively and by incorporating into nascent viral DNA, resulting in DNA chain termination and significant reduction of viral replication.