Antivirals Flashcards
Most viruses are composed of what?
proteins and nucleic acids
What virus is not composed of proteins and nucleic acids?
prions
What do viruses require to replicate?
host cellular machinery
Viruses are obligate _________ parasites.
intracellular
Where do almost all DNA viruses replicate?
nucleus
All viral RNA is single stranded. (T/F)
False: single or double stranded
Describe the general replication cycle
- attachment
- penetration/entry
- un-coating
- transcription
- translation
- replication
- assembly
- release
Viruses are more difficult to treat than bacterial infections. (T/F)
True
What is the main reason viruses are more difficult to treat than bacterial infections?
intracellular nature
Antivirals are generally (more/less) toxic when compared to anti-infectives.
more
What are the 3 main concerns with antiviral medications?
- drug delivery
- drug concentrations
- resistance
Most antiviral agents have (robust/sparse) effect on latent viruses.
sparse
What are the main reasons why we cannot cure HIV? (5)
high genetic - variability - functionality - turnover memory cells reservoir seeding
What are the 7 antiretroviral drug classes?
- nucleoSide reverse transcriptase inhibitor
- nucleoTide reverse transcriptase inhibitor
- non-nucleoside reverse transcriptase inhibitor
- protease inhibitor
- integrase inhibitor
- fusion inhibitor
- co-receptor inhibitor
What class does AZT belong to?
nucleoSide reverse transcriptase inhibitor
What class does Tenofovir belong to?
nucleoTide reverse transcriptase inhibitor
What class does Efavirenz belong to?
non-nucleoside reverse transcriptase inhibitor
What class does Tipranavir belong to?
protease inhibitor
What class does Raltegravir belong to?
integrase inhibitor
What class does Enfurvitide belong to?
Fusion inhibitor
What class does Maraviroc belong to?
Co-receptor inhibitor
What is the minimum number of medications to treat HIV?
3
Do ARVs eradicate virus or retard viral replication?
retard viral replication
Which ARVs have efficacy against Hep B?
- lamivudine
- emtricitabine
- adefovir
- tenofovir
What are some proposed curative techniques for HIV?
- vaccine
- viral coaxing and intesification
- gene therapy
- BMT
What is acyclovir used to treat?
- HSV-1
- HSV-2
- VZ
- some efficacy against CMV and EBV
What is the MOA of acyclovir?
Acyclovir triphosphate competes with endogenous substrates for binding to viral DNA polymerase. Once incorporated into the growing DNA chain, further synthesis is halted.
Acyclovir is a ________ analog converted by viral _______ ______ in infected cells to acyclovir ____phosphate which is converted to acyclovir ____phosphate.
- guanosine
- thymidine kinase
- mono
- tri
Acyclovir is commonly used for (suppression/treatment) of genital herpes.
both suppression and treatment
Resistance is (common/rare) for acyclovir.
common
What are the most common ADRs with acyclovir?
CNS related and rare
Acyclovir is available in what dosage forms?
PO, IV, topical
How are acyclovir and valacyclovir related to each other?
Valacyclovir is the prodrug form of acyclovir
What is the goal of using a prodrug of acyclovir (valacyclovir)?
to enhance drug delivery
Valacyclovir serum levels approach those of what?
IV acyclovir
How is the spectrum of activity of valacyclovir different from acyclovir?
it is identical to acyclovir spectrum
Valacyclovir has a (more complex/simpler) dosing regimen than acyclovir.
simpler
In what dosage form is penciclovir available?
topical
What is the oral bioavailability of penciclovir?
poor
Penciclovir should be administered q__ for what condition?
- q 2 hours
- herpes labialis
Famciclovir is the prodrug of what?
penciclovir
What is the benefit of formulating penciclovir in a prodrug form?
famciclovir has good oral absorption
For what conditions is famciclovir indicated?
- recurrent HSV
- HZ
What is the MOA of ganciclovir?
nucleoside analog of guanine that eventually results in DNA chain termination within infected cells
What is the primary indication of ganciclovir?
control/treatment of CMV
What are less common indications of ganciclovir?
- HIV
- solid organ transplant
What is PO ganciclovir indicated for?
suppression of CMV
What is IV ganciclovir indicated for?
treatment of CMV
What antiviral has 10 times more potency against CMV?
ganciclovir
What is the prodrug of ganciclovir?
valganciclovir
When might valganciclovir be indicated?
PO treatment of CMV
What is the main ADR of ganciclovir?
neutropenia
What medication is an inorganic pyrophosphate?
Foscarnet
Foscarnet has a (wide/specific) spectrum of activity.
wide