Lamivudine is a reverse transcriptase inhibitor used to treat HIV and hepatitis B infections. It is a nucleoside reverse transcriptase inhibitor (NRTI) that targets HIV infected cells in the body. When HIV infects a cell, the virus first binds and fuses with the cell, releasing its nucleocapsid containing its RNA and reverse transcriptase into the cytosol of the cell. The reverse transcriptase converts the viral RNA into viral DNA in the cytosol. The viral DNA goes to the nucleus through the nuclear pore complex where it undergoes the process of transcription. The new viral RNA formed from transcription is transported back to the cytosol through the nuclear pore complex and translation occurs to produce viral proteins. These viral proteins are assembled and new HIV viruses bud from the cell. Lamivudine enters the cell via solute carrier family 22 member 2 and is converted into lamivudine monophosphate by deoxycytidine kinase. UMP-CMP kinase protein then converts lamivudine monophosphate into lamivudine diphosphate. The lamivudine diphosphate is metabolized to lamivudine triphosphate via nucleoside diphosphate kinase A or phosphoglycerate kinase 1. Limuvudine triphosphate is an analog of deoxycytidine-5'-triphosphate (dCTP). Lamivudine triphosphate inhibits the activity of HIV-1 reverse transcriptase by competing with its substrate, dCTP and by incorporation into viral DNA. Lamivudine triphosphate lacks the 3'-OH group which is needed to form the 5′ to 3′ phosphodiester linkage essential for DNA chain elongation, therefore, once lamivudine triphosphate gets incorporated into DNA, this causes DNA chain termination, preventing the growth of viral DNA. Less viral proteins are therefore produced, and there is a reduction in new viruses being formed. Common side effects from taking lamivudine include headache, nausea, vomiting, diarrhea, weight loss, abdominal pain, fever, cough and nasal signs & symtpoms.

Lamivudine Anti-viral Pathway References