17: Antiviral Drugs Flashcards
What is a vaccine?
Vaccines can prevent viral diseases but there’s no effect on individuals that are already infected
What is an antiviral drug?
Antiviral drugs can stop the infection once it starts. There’s about 100 antiviral drugs approved by the FDA against HIV,HCV and herpesvirus
Why are there few antiviral drugs?
- Compounds interfering with virus replication can adversely affect the host cell
- Every step of the viral reproduction cycle engages host function
- There are no animal models can be dangerous.
- HBV and HPV
- Smallpox
- Ebolavirus
Why is studying the infectious cycle important?
- Knowledge of viral reproduction cycles identifies general targets for antiviral drug discovery
What is the drug discovery pathway, describe the phases?
1) Drug is tested in increasing doses with a small group of people
2) Test the effectiveness of interventions in people who have a disease
3) Test the effectiveness of the pre drugs in comparison to current drugs
What is the mechanism-based screening for antiviral compounds? Using Inhibitor of viral protease.
Setup: A peptide (matching the protease’s target site) is attached to a bead, along with a fluorescent molecule.
Protease Action: If the protease is active, it cuts the peptide, releasing the fluorescent molecule into the solution.
Drug Test:
*If the drug blocks the protease, the fluorescent molecule stays on the bead, resulting in low fluorescence.
*If the drug doesn’t work, the protease cuts the peptide, releasing the fluorescent molecule, causing high fluorescence.
Fluorescence levels indicate the drug’s effectiveness.
What is high-throughput screening of a virus?
It is a screen for binding of antiviral drugs to binding sites target protein.
Combinatorial chemistry
What are the targets for antiviral drugs in reproduction cycle in HIV?
- Attachment & entry inhibitors
- Fusion inhibitors - Reverse transcriptase inhibitors
- Integrase inhibitors - Protease inhibitors
What is Maraviroc?
- It is an inhibitor of attachment of HIV-1 to CCR5
What is Azidothymidine?
It is a reverse transcriptase inhibitor.
It is a thymidine analog and is used to treat AIDS. It is phosphorylated by cellular enzymes and incorporated into viral DNA and acts as a chain terminator.
What is Saquinavir?
It is a protease inhibitor.
It acts by binding to the catalytic site of HIV protease and prevents the cleavage of viral polyprotein precursors into mature, functional proteins and needed for viral replication/
What is favipiravir?
- Broad spectrum inhibitor of RNA viruses
- Targets RdRp, nucleoside analogue
- effective with many (+) and (-) RNA viruses
- Japan
