Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology Infectious Disease > Antivirals > Flashcards

Antivirals Flashcards

1
Q

How do antivirals creat specificity if they are targeting the virus or the host cell?

A

Virus: Target viral-specific enzymes (proteases, mRNA capping proteins, integrases, neuraminadases, ribonucleases, kinases, uncoating)
Host cell: drug activated in ONLY infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the theraputic window for antivirals? Definition and numerical value.

A

Ratio - Toxicity dose for host:Toxicity dose to virus

For antivirals = 100 - 1000 = 100 to 1000 times more toxic to the virus than the host.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What combinations are used for HAART?

A

Highly Active Anti-Retroviral Therapy: 2 NRTIs + 1 NNRTI OR 1 Protease Inh OR 1 Integrase Inh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How effective are antivirals? WHy is this important?

A

All viroSTATIC. Means that an intact immune system needed to suppress most viral infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is difficult about treating chronic infections?

A

viral latency - drugs don’t work; erradication is nearly impossible.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does viral uncoating in non-enveloped and membrane-containing viruses entail?

A

Loss of nucleocapsid proteins (non-enveloped), Loss of lipid envelope/membrane in endolysosome. If in endolysosome = pH dependent uncoating (

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the best available class of antivirals and why?

A

Inhibition of viral genome replication: Specificity:

1) virus can use its own enzyme for activation
2) viral polymerases are more sensitive to drug harm

Next most widely used: IFN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of a virus carrying a thymidine kinase? How is it used in drug mechanism of action?

A

Virus - can use for replication in cells not actively dividing and lack phosphorylated nucleic acids.
Used to activate drugs in infected cells only.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

For drugs that are activated by viral thymidine kinases, what confers their specificity? What is one added benefit of having the drug phosphorylated by the virus?

A

Viral thymidine kinases - sloppy/non-specific and phosphorylate the drug. Host thymidine kinases don’t phosphorylate drug (more selective). Viral phosphorylation means you can administer non-phosphorylated = better cell entry.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

For inhibiton of viral nucleic acid synthesis, how does chain termination work?

A

Irriversible binding to the polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the targets for antiviral therapy? Which target only has one class of drugs that work for it?

A

Cell entry & Uncoating, Nucleic acid synthesis & polymerases, mRNA post-transcriptional modifications (ONLY IFN FOR THIS), Proteases, Viral release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What antivirals inhibit cell entry (viruses in general and HIV; 2 for each)?

A

Amatadine, Rimantadine

HIV: Maraviroc, Enfuvitide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What antivirals Inhibit Nucleic Acid Synthesis (5 gen viruses, 3 HIV)?

A

Idoxuridine, Ribavirin, Acyclovir, Foscarnet, Cidofovir

HIV: NRTIs (AZT, Lamivudine), NNRTIs, Raltegravir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What drugs inhibit viral release?

A

Zanamivir, Oseltamivir, Maybe Amatadine (HA maturation inhibition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What antivirals inhibit proteases (2 gen viruses, 1 class HIV)?

A

Asuprenavir, Telaprevir - HCV serine protease

HIV: Protease inhibitors - “navir” (e.g. Indinavir)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which nucleic acid synthesis inhibitors are activated by a viral kinase?

A

“ovir”, idoxuridine, ribavirin, NRTIs (except AZT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which antivirals bind specific proteins OR have a higher affinity for their substrates?

A

Specificity:
Zanamivir, Oseltamivir - viral N.A.
Asuprenavir/Telapravir - HCV serine protease
“navir” HIV protease inhibitors - HIV aspartyl protease
Raltegravir - HIV integrase
Increased affinity:
Acyclovir - viral thymidine kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What drugs are used to treat HSV?

A

Acyclovir, Idoxuridine

19
Q

What drugs are used to treat HepC infection?

A

INF-alpha
Ribavirin
Asuprenavir, Telaprevir
“navirs” - HIV protease inhibitors

20
Q

Name 3 drugs used or in trial for pre-exposure prophylaxis.

A
  1. Nevipine, AZT - Reduce HIV transmission to fetus
  2. Maraviroc - In testing for HIV prophylaxis in combo w/ emtricitabe, tenofovir
  3. Oseltamivir, Zanamivir - Influ A high risk populations
21
Q

What are the mechanisms of actions of interferons?

A

Induce an antiviral state in the adjacent cell:

  1. Iinhibit RNA post-translational modifications (processing, capping, adenylation, splicint)
  2. Inhibit translation
  3. Enhance MHC I expression on infected cells.
22
Q

What drugs are used in CMV treatment?

A

Gancyclovir (first line), Acyclovir, Foscarnet, Cidofovir

23
Q

Name 5 drugs used to treat influenza. What are the advantages to each?

A

Zanamivir (aerosol), Oseltamivir (oral) - Influ A & B, M2 inh and uncoating inhibition
Amantidine, Rimantadine - Influ A only; Riman better than Amant in renal failure; not used frequently
Gamma globulins

24
Q

When should antivirals for influenza be taken?

A

W/ in 48 hours of the illness presentation.

25
Q

What is Ribavirin used for?

A

Broad spectrum, esp RSV, chronic HepC, HIV, influenza, hemorrhavic fevers.

26
Q 
Name the mechanisms of action of the following:
Idoxuridine
Ribavirin
Acyclovir
Valacyclovir
Famciclovir
Gancyclovir
Valganciclovir
Foscarnet
Cidofovir
A

Idoxuridine - Pyrimidine analog, chain termination
Rivavirin - Guanosine analog, IMP DH/guanosine synthesis inhibition; inhibit mRNA pol; inhibit mRNA capping
Acyclovir (Valacyclovir, Famcyclovir) - Guanosine analog, chain termination
Gancyclovir (Valganciclovir) - Guanosine analog, chain termination
Foscarnet - DNA pol and RT inhibitor
Cidofovir - DNA pol inhibitor

27
Q

Why is gancyclovir first line for CMV?

A

It can be activated by the host kinase, and CMV can lack a viral thymidine kinase.

28
Q

What is used as an alternative to the orthomyxovirus vaccine in the elderly?

A

Amantadine

29
Q 
What are the mechanisms of the following?
Asuprenavir
Telaprevir
Zanamivir
Oseltamivir
A

Asuprenavir, Telaprevir - Inhibit HCV serine protease

Zanamivir, Oseltamivir - Bind NA and prevent viron release.

30
Q

What are the actions of alpha, beta, and gamma interferons?

A

alpha and beta - secreted by viral infected cells, induce antiviral state in adjacent cell, enhance MHC expression

gamma - T cells secrete; enhances cell mediated immunity

31
Q

What is lamivudine often used in combo with and for?

A

HIV - AZT
HBV - adofovir
combination helps prevent resistance

32
Q

Which antiviral can only be used topically and why?

A

Idoxuridine - to toxic for systemic use: Leukopenia, Hepatotoxicity, GI upset

33
Q

What antivirals are contraindicated in pregnancy?

A

Ribavirin, Gancyclovir

34
Q

What are some pros and cons of Acyclovir use?

A

Pro: Very selective for viral thymidine kinase, widly distributed (to the CNS), all forms of administration possible
CONS: Tissue irritation w/ extravasation, Nephrotoxicity, GI upset

35
Q

Why might you use the precursors to acyclovir and gancyclovir, valacyclovir and valganciclovir?

A

Better oral bioavailability

36
Q

What are the toxicities of gancyclovir?

A

Leukopenia, thrombocytopenia, mutagen, tetratogen, nephrotoxicity

37
Q

What antivirals are nephrotoxic?

A

Acyclovir
Gancyclovir
Foscarnet
Cidofovir (coadminister w/ probenecid & saline)

38
Q

What is the treatment for severe influenza?

A

Zanamivir or oseltamivir w/ in 48 hours. Decreases illness duration and reduces risk of complications.

39
Q

For a pateint who is <1 year old, what would you use to treat severe influenza infection?

A

Zanamivir

40
Q

What antiviral is contraindicated in patients with respiratory disease?

A

Oseltamivir

41
Q

What are the toxicities associated with Interferons?

A

Neutropenia, myopathy, neurotoxicity

42
Q

What are the toxicities associated with the following HIV drugs?
Protease inhibitors
NRTIs

A

Protease inhibitors: Hyperglycemia, GI intolerance, lipodystrophy (increased TG and LDL)

NRTIs: Bone marrow suppression, peripheral neuropathy

43
Q

What might you use G-CSF and EPO to treat?

A

Bone marrow suppression caused by HIV NRTIs

44
Q

What anti-HIV medications:
1) inhibit CYP 450
2) Use/compete for the glucuronyl transferase pathway
why is this important?

A

1) Ritonavir (protease inhibitor) - CYP450 inhibitor

2) AZT - severe reactions w/ asprin, tylanol, others that use glucuronidation in liver.

Pharmacology Infectious Disease (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions