Antivirals Flashcards
What are the two types of virus’s?
DNA (chronic) and RNA (acute)
Name some acute viral infections
Influenza, measles, mumps, hep A
Name some chronic viral infections
Latent with/without recurrences
- Herpes simplex, cytomegalovris
- Persistent - HIV, Hep B, Hep C
Viruses consist of..
- RNA/DNA
- Protein (coat = structural; enzyme = non-structural)
- lipid envelope (some) (acquire from cell they invade)
Viruses can be described as
Obligate intracellular parasite - how to invade cell in order to survive and replicate
Virus replication cycle - name the key steps
- Virus entry into body
- virus attachment to cell
- Viral entry into cell
- Uncoating of virus
- Early proteins produced (enzymes)
- Replication
- Late transcription/translation
- Virus assembly
9 Virus release - lysis
What do most antivirals act on?
Viral polymerases by mimicking nucleotides (directly or terminate chain formation)
NRTIs?
Nucleotide Reverse Transcriptase Inhibitors
Name pyrimidine analogues (-vudine)
Thymidine - zidovudine
Cytosine - lamivudine
Name purine inhibitors (-vir)
Tenofovir
Abacavir
What affects both HIV and Hep B?
Lamivudine
Tenofovir
What are protease inhibitors? (-navir)
Prevent viral replication by binding to viral proteases, preventing viral cleavage of protein precursors needed for production of infectious viral participles.
What are the main classes of antiviral?
- Fusion inhibitors - prevents HIV fusion to CD4 (blocks Gp120)
- CCR5 antagonists - prevents HIV entry (prevents binding to CCR5)
- Nucleotide reverse transcriptase inhibitors
- Non-nucleotide reverse transcriptase inhibitors
- Integrase inhibitor - blocks integrase - enzyme that inserts viral DNA into DNA of host cell
- protease inhibition - prevents HIV maturation
One of first drugs for HIV?
AZT - not used due to resistance development
Highly active antiretroviral therapy - what is it and why?
Used to prevent resistance - use of 2-3 different treatments to prevent resistance. Taken life long. Suppression >10years is usually achieved!
