B5.030 Viral Hepatitis Large Group Flashcards
tenofovir disoproxil mechanism
nucleotide analog of adenosine monophosphate and a reverse transcriptase inhibitor
tenofovir uses
inhibits viral reverse transcriptase of HIV and HBV
limited inhibition of human enzymes
lamivudine 3TC) mechanism
analogue of cytidine
antiretroviral medication
can inhibit both types of HIV reverse transcriptase and the reverse transcriptase of HBV
phosphorylated to active metabolites that compete for incorporation into viral DNA
use competitive inhibition and act as a chain terminator of DNA synthesis
lamivudine uses
used to prevent and treat HIV and chronic HBV (when other options are not possible)
downside to lamivudine
rapid resistance develops
30% after 2 years, 70% at 5 years
entecavir mechanism
deoxyguanosine analogue that inhibits reverse transcription, DNA replication and transcription in the viral replication process
adefovir dipivoxil mechanism
blocks reverse transcriptase
resistance doesn’t develop as quickly as with lamivudine
telbivudine mechanism
synthetic thymidine B-L-nucleoside analogue
intracellularly phosphorylated to the active triphosphate form, which competes with the natural substrate to inhibit HBV reverse transcriptase
reduces DNA replication by chain termination
combined HIV/HBV agents
tenofovir
lamivudine
chemical HBV agents
entecavir
adefovir dipivoxil
telbivudine
what is the function of IFN-a in HBV treatment
predominantly immunomodulatory effects
cytokine also exerts a limited direct antiviral effect
mechanism of IFN-a
binds to cellular receptor and activates secondary messengers, resulting in the production of multiple proteins that are important for the defense of the cell against viruses
immunomodulatory effects of IFN-a
enhancement of antigen presentation to immune system
activation of NK cells and other immune cells
production of cytokines
antiviral effects of IFN-a
degradation of viral mRNA
inhibition of viral protein synthesis
prevention of infection of cells
primary test for hep B screening
HBsAg
hep B viral load used for quantitative measure