Lamivudine- Anti Viral Drug

Lamivudine

Introduction
A reverse transcriptase inhibitor and zalcitabine analog in which a sulfur atom replaces the 3' carbon of the pentose ring. It is used to treat Human Immunodeficiency Virus Type 1 (HIV-1) and hepatitis B

Pharmacological Action
For the treatment of HIV infection and chronic hepatitis B (HBV). Lamivudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1) and hepatitis B (HBV). Lamivudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated.

Uses
Mainly used in treatment of hepatitis B.
In low dose it is also used in treatment of HIV AIDS.

Side Effect
Cough
Diarrhea
Nasal congestion
Headache
Inflammatory response

Drug Drug Interaction
Ribavirin + Lamivudine = Ribavirin increases the hepatotoxic activity of lamivudine.
Trimethoprine + Lamivudine = Trimethoprine may decrease the excretion of lamivudine.

Reference- Tripathi KD "Essential of medical pharmacology" 7th edition, page no- 798,803,807-08,811,813,815