Category: Entecavir

What is Hepatitis B? Hepatitis B is a form of hepatitis derived from a DNA virus that causes liver infections in humans and animals. Hepatitis B virus belongs to a family of viruses called hepadnaviridae (hepa = liver, dna = deoxyribonucleotide, viridae = virus). All known hepadnaviridae are hepatotropic (affecting liver cells) and contain double-stranded…

HBV is spread by direct contact with blood or body fluids of an infected person, such as: Unprotected sexual contact Blood transfusion Sharing of contaminated needles and syringes Vertical transmission from mother to child during childbirth Contact via the lips could also cause the spread of the virus, especially if the infected person has a…

Structure: The hepatitis B virus is a double-shelled spherical particle with a diameter of 42-47 nm (4). It consists of icosahedral nucleocapsid (protein core) enclosing a circular, double-stranded DNA genome. The outer lipid envelope contains embedded proteins (HB surface antigens) which are involved in viral binding of susceptible cells. Genome: The hepatitis B virus genome is a relaxed circular,…

After initial infection, hepatitis B virus DNA, hepatitis B c-antigen, hepatitis B s-antigen, and hepatitis B e-antigen are detectable in the bloodstream. If you are unfamiliar with the term antigen, it is a component of the virus (or any pathogen), such as a particular protein it possesses, that can be detected by an antibody produced in…

Background Information Entecavir (ETV) is an FDA approved medicine used to treat chronic hepatitis B virus infection in adults who have active liver damage. ETV belongs to the nucleoside analogue reverse transcriptase inhibitor class of drugs and is sold under the brand name Baraclude. It is a product of Bristol-Myers Squibb Pharmaceutical Research Institute. ETV…

Once ETV enters the cell, cellular kinases phosphorylate it into an active triphosphate compound. It is important to note that other than the cells phosphorylation efficiency, a combination of intrinsic potency, exposure level, and genetic barriers to resistance also contribute to the initial and long-term effectiveness of ETV. ETV inhibits the only known enzymatic target…

Antiviral Activity The ETV EC50 of a laboratory HBV isolate in cell culture is 5.3 nM (7). This suggests that ETV is very responsible, even at low doses. In two relevant animal models, daily or weekly ETV treatment significantly reduced viral levels. Long-term studies demonstrated that oral weekly dosing of 1 mg/kg maintained viral DNA levels…

The only way to cure or to protect oneself from a viral infection is to be born with a strong immune system or be vaccinated prior to infection, respectively. A vaccine simply increases the immune systems arsenal against future foreign invaders by allowing the body to produce antibodies against viral antigens prior to infection, rather…