Flashcards in Antivirals Deck (32):
What are the stages in the pathogenesis of HIV
1) HIV contracted
3)host immune system contains it
4) latent phase
5)overtime CD4 falls as does the immune function.
7) Initially non- specific.
How is HIV contracted
mother to baby, sex or IV
Drug used for HIV
T3-3 Drugs in one.
What type of viruses cause acute infection.
Examples of acute infections
Influenza, measles, mumps, hepatitis A virus.
What type of viruses cause chronic infection
2 types of chronic viral infection.
Latent- come out under stress.
Persistent-replicate all the time and are found in blood- HIV, Hep B.
What does viruses consist of
nucleic acid- DNA or RNA
lipid envelope derived from the cells they grow in.
why don't viruses which infect the GI tract have an envelope
to withstand the ph- envelope proteins would otherwise be destroyed.
which 2 gene types make up a virus
Structural- make virus
Non-structural- take over host machinery.
Mechanism of viral replication
1) virus attaches to a cell
2) cell entry
3) virus uncoating
4) early proteins produced.
6)Latent transcription and translation
Prime target of antivirals
How does AZT (azidothymidine) work
mimics the binding blocks used for DNA and RNA synthesis.
changes OH group to NH3 on bases.
what type of antiviral is AZT
Nucleoside reverse transcriptase Inhibitor.
2 types of NRTI's
Pyrimidine analogues.- C an T
Purine analogues.- A and G.
Adenine and Guanidine analogues
NRTI's active against HBV
Examples of non- nucleoside reverse transcriptase (NNRTI's)
How do NNRTI work
Bind to different parts of the polymerase and inhibit it.
Examples of protein inhibitors.
Ritonavir*- now used to boost the level of other protein inhibitiors which are brokendown by liver enzymes.
How does fusion inhibitors work and a example
block virus fusing with membrane- given IM
How do Intergrase inhibitors work
prevents virus incorporating in the host genome. Not toxic.
How do Chemokine receptor antagonsits work
prevent s entry
HIV requires CC5 to enter the cell as it is a co- receptor.
What does HAART stand for
Highly active antiretroviral therapy
What does HAART consist of and what is it's function
– 2 NRTIs + NNRTI
– 2 NRTIs + boosted PI
Aims to switch of virus replication can cause liver toxicity.
what mutation arises due to resistance to Lamivudine
What mutation provides resistance to HIV.
CCR5 delta 32 - chnage in CCR5 means that HIV cannot bind
2 drugs which sure Hep C
Interferons and ribavirin
How long do interferons need to be given for