HEPTAVIR-150 Tablets HEPTAVIR-150 contains Lamivudine, a synthetic nucleoside analogue of cytidine. Lamivudine is intracellularly phosphorylated to its active metabolite, lamivudine 5'-triphosphate (3TC-TP). 3TC-TP functions as a substrate for and competitive inhibitor of HIV-1 reverse transcriptase and Hepatitis B Virus (HBV) DNA polymerase. Its incorporation into viral DNA results in DNA chain termination due to the absence of a 3'-hydroxyl group necessary for continued elongation. It is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection and for the management of chronic hepatitis B infection.