Mechanism Of Action Of Antivirals Flashcards
What are the current uses of antiviral drugs?
Treatment of acute infection
Treatment of chronic infection
Post-exposure prophylaxis and preventing infection
Prophylaxis for reactivated infection
How does selective toxicity work?
Target protein in virus, not the infected cell
What are the modes of action of amantadine?
Blocks low pH endosome dependant on coating M2 protein
What are the modes of action of acyclovir, ganciclovir and ribavarin?
Inhibit nucleic acid polymerisation
What are the modes of action of ribavarin?
Guanine analogue RSV
What are the modes of action of AZT?
Blocks HIV reverse transcriptase to prevent formation of dsDNA proteins from the HIV RNA genome
What are the types of herpesvirus?
Herpes simplex
Varicella zoster virus
Cytomegalovirus
Epstein-Barr virus
What does acyclovir treat?
HSV, VZV treatment and prophylaxis
How does acyclovir work?
Activated by the viral enzyme thymidine kinase
- > adds phosphates which makes it look like a base so it is incorporated into the viral DNA
- > very selective
What does ganciclovir treat?
CMV
How does ganciclovir work?
Inhibits CMV DNA polymerase by inhibiting V19 kinase
What are the main mechanisms of antiviral resistance in herpes?
Thymidine kinase mutants
DNA polymerase mutants
What is the HIV membrane associated matrix protein?
Gag 17
What is the HIV Nucleocapsid protein?
Gag p24
What is the HIV envelope protein?
Gp120 with transmembrane gp41
What are the types of anti-HIV drugs?
Anti-reverse transcriptase inhibitors
Protease inhibitors
Integrase inhibitors
Fusion inhibitors
What are nucleoside reverse transcriptase inhibitors?
Synthetic analogue of nucleoside thymine
What are non-nucleoside reverse transcriptase inhibitors?
Non-competitive inhibitor for HIV-1 reverse transcriptase
What is a viral swarm?
When all possible viral variants are produced within one patient
How do zanamivir and osetamivir work?
Inhibits virus release from infected cells via inhibition of neuraminidase
How does ribavarin work?
Blocks RNA synthesis by inhibiting inosine 5’ monophosphate dehydrogenase
Stops GTP synthesis and therefore RNA synthesis
How do direct-acting antivirals work?
Target specific steps in the HCV viral life cycle
What are the incurable viruses?
Rabies Dengue Common cold Ebola HPV Arboviruses Pathogen X
What is pathogen X?
Stuff we don’t know about yet
