Antivirals Flashcards
What polymerase must be encoded by RNA viruses?
RNA-dependent RNA polymerase (must get from + to -)
Acyclovir requires phosphorylation by what to become active?
viral thymidine kinase
Why is acyclovir so specific?
It has greater affinity for viral polymerase vs cellular polymerase, AND it is phosphorylated mainly in virus infected cells
Acyclovir MOA?
Deoxyguanosine analog that terminates chain of DNA
Ganciclovir is phosphorylated by what?
CMV kinase
Why is ganciclovir more toxic?
it can be phosphorylated by a CMV kinase or by cellular kinases
Influenza virus has _____ RNA genome
segmented
Anti-flu drugs target what 3 structural components?
HA, NA, and M2
2 important Adamantanes?
Amantadine and Rimantadine
Adamantane MOA?
inhibit M2 protein so virus can’t uncoat
Oseltamivir and Zanamivir MOA?
neuraminidase inhibitors; new virus can’t release from cell membrane
Adamantanes are effective against what kind of flu?
A
Oseltamivir and Zanamivir are effective against what kind of flu?
A and B
Ribavirin is used to treat ___
Hep C (combo therapy)
Ribavirin MOA?
nucleoside analog that interferes with viral nucleic acid synthesis
Main goal in treating HIV?
control of HIV replication
4 main classes of antiretroviral agents?
reverse transcriptase inhibitors, integrase inhibitors, fusion/entry inhibitors, protease inhibitors
2 main enzymes that HIV encodes?
reverse transcriptase and integrase
3 kinds of RT inhibitors to know?
Nucleotide RT Inhibitors, nucleoside RT inhibitors, non-nucleoside RT inhibitors
Best tactic to avoid HIV resistance?
strict adherence to meds
Why is HAART effective?
Use a lot of drugs/combinatorial therapy - resistance becomes less likely and the drugs work for a long time
The most common flu drugs block the beginning and the end of the viral infection cycle. Identify which targets the beginning and which targets the end.
beginning = M2 ion channel (virus can’t uncoat); end = neuraminidase
