Antivirals Flashcards
(135 cards)
1
Q
Most viruses are composed of what?
A
proteins and nucleic acids
2
Q
What virus is not composed of proteins and nucleic acids?
A
prions
3
Q
What do viruses require to replicate?
A
host cellular machinery
4
Q
Viruses are obligate _________ parasites.
A
intracellular
5
Q
Where do almost all DNA viruses replicate?
A
nucleus
6
Q
All viral RNA is single stranded. (T/F)
A
False: single or double stranded
7
Q
Describe the general replication cycle
A
- attachment
- penetration/entry
- un-coating
- transcription
- translation
- replication
- assembly
- release
8
Q
Viruses are more difficult to treat than bacterial infections. (T/F)
A
True
9
Q
What is the main reason viruses are more difficult to treat than bacterial infections?
A
intracellular nature
10
Q
Antivirals are generally (more/less) toxic when compared to anti-infectives.
A
more
11
Q
What are the 3 main concerns with antiviral medications?
A
- drug delivery
- drug concentrations
- resistance
12
Q
Most antiviral agents have (robust/sparse) effect on latent viruses.
A
sparse
13
Q
What are the main reasons why we cannot cure HIV? (5)
A
high genetic - variability - functionality - turnover memory cells reservoir seeding
14
Q
What are the 7 antiretroviral drug classes?
A
- nucleoSide reverse transcriptase inhibitor
- nucleoTide reverse transcriptase inhibitor
- non-nucleoside reverse transcriptase inhibitor
- protease inhibitor
- integrase inhibitor
- fusion inhibitor
- co-receptor inhibitor
15
Q
What class does AZT belong to?
A
nucleoSide reverse transcriptase inhibitor
16
Q
What class does Tenofovir belong to?
A
nucleoTide reverse transcriptase inhibitor
17
Q
What class does Efavirenz belong to?
A
non-nucleoside reverse transcriptase inhibitor
18
Q
What class does Tipranavir belong to?
A
protease inhibitor
19
Q
What class does Raltegravir belong to?
A
integrase inhibitor
20
Q
What class does Enfurvitide belong to?
A
Fusion inhibitor
21
Q
What class does Maraviroc belong to?
A
Co-receptor inhibitor
22
Q
What is the minimum number of medications to treat HIV?
A
3
23
Q
Do ARVs eradicate virus or retard viral replication?
A
retard viral replication
24
Q
Which ARVs have efficacy against Hep B?
A
- lamivudine
- emtricitabine
- adefovir
- tenofovir
25
What are some proposed curative techniques for HIV?
- vaccine
- viral coaxing and intesification
- gene therapy
- BMT
26
What is acyclovir used to treat?
- HSV-1
- HSV-2
- VZ
- some efficacy against CMV and EBV
27
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.
28
Acyclovir is a ________ analog converted by viral _______ ______ in infected cells to acyclovir ____phosphate which is converted to acyclovir ____phosphate.
- guanosine
- thymidine kinase
- mono
- tri
29
Acyclovir is commonly used for (suppression/treatment) of genital herpes.
both suppression and treatment
30
Resistance is (common/rare) for acyclovir.
common
31
What are the most common ADRs with acyclovir?
CNS related and rare
32
Acyclovir is available in what dosage forms?
PO, IV, topical
33
How are acyclovir and valacyclovir related to each other?
Valacyclovir is the prodrug form of acyclovir
34
What is the goal of using a prodrug of acyclovir (valacyclovir)?
to enhance drug delivery
35
Valacyclovir serum levels approach those of what?
IV acyclovir
36
How is the spectrum of activity of valacyclovir different from acyclovir?
it is identical to acyclovir spectrum
37
Valacyclovir has a (more complex/simpler) dosing regimen than acyclovir.
simpler
38
In what dosage form is penciclovir available?
topical
39
What is the oral bioavailability of penciclovir?
poor
40
Penciclovir should be administered q__ for what condition?
- q 2 hours
| - herpes labialis
41
Famciclovir is the prodrug of what?
penciclovir
42
What is the benefit of formulating penciclovir in a prodrug form?
famciclovir has good oral absorption
43
For what conditions is famciclovir indicated?
- recurrent HSV
| - HZ
44
What is the MOA of ganciclovir?
nucleoside analog of guanine that eventually results in DNA chain termination within infected cells
45
What is the primary indication of ganciclovir?
control/treatment of CMV
46
What are less common indications of ganciclovir?
- HIV
| - solid organ transplant
47
What is PO ganciclovir indicated for?
suppression of CMV
48
What is IV ganciclovir indicated for?
treatment of CMV
49
What antiviral has 10 times more potency against CMV?
ganciclovir
50
What is the prodrug of ganciclovir?
valganciclovir
51
When might valganciclovir be indicated?
PO treatment of CMV
52
What is the main ADR of ganciclovir?
neutropenia
53
What medication is an inorganic pyrophosphate?
Foscarnet
54
Foscarnet has a (wide/specific) spectrum of activity.
wide
55
What is the MOA of foscarnet?
Binds and inactivates DNA polymerase without any requirement for phosphorylation by TK
56
What is a proposed place in therapy for foscarnet?
potential in resistant cases
57
What is the spectrum of activity for foscarnet?
- HSV 1
- HSV 2
- CMV
- Influenza A and B
- HIV
- Hep B
58
When is foscarnet most commonly used?
treatment of resistant CMV and HSV
59
Why is foscarnet not used more often?
highly intolerable with significant dose-limiting renal toxicity
60
Foscarnet is available in what dosage form?
IV
61
What is the administration method of foscarnet that helps to prevent renal toxicity?
pre-hydration with NS
62
What is the chemical class of cidofovir?
acyclic nucleoside phosphate derivative
63
What is the spectrum of activity for cidofovir?
- HSV 1
- HSV 2
- VZ
- EBV
- CMV
64
What specific mechanism allows cidofovir to be useful in resistant cases?
Does not require TK phosphorylation for activation
65
In what patients is cidofovir indicated?
CMV-infected AIDS patients with foscarnet/ganciclovir intolerance or resistance
66
Cidofovir is available in what dosage form?
IV only
67
What is the main ADR of cidofovir?
nephrotoxicity
68
What is the administration method of cidofovir that helps to prevent renal toxicity?
pre-hydratewith NS and consider addition of oral doses of probenecid
69
What is the purpose of co-administering probenecid with cidofovir?
probenecid prevents secretion of cidofovir
70
What are the first generation Hep C drugs?
- ribavirin
| - interferons
71
What is the MOA of ribavirin?
interference with several key viral replication steps, primarily at the transcription level
72
What is the spectrum of activity for ribavirin?
- Influenza A and B
- mumps
- measles
- parainfluenza
- HSV
- Hep B
- Hep C
- RSV
73
What is the most common use of ribavirin?
heptidic disease
74
In patients with hepatitis, ribavirin is commonly combined with what?
interferons
75
Ribavirin is available in what dosage forms?
PO
76
What is the pregnancy category for ribavirin?
X - teratogenic
77
Contraception is required for _________ post-treatment with ribavirin.
6 months
78
What are the ADRs of ribavirin?
- nausea
- headache
- lethargy
79
Exact MOA of interferons varies with what?
concentrations and presence or absence of other interferons/interleukins
80
Interferon-α is believed to induce what antiviral changes in exposed and infected cells?
- induction of proteins that inhibit DNA synthesis
- promotion of enzymes that cleave both cellular RNA and DNA
- alteration of cell membranes to block viral release from infected cells
81
What is the typical route of administration of interferons?
- Sub Q
| - IM
82
Interferons are combined with ribavirin when treating what?
Hep B and C
83
What are ADRs of interferons?
- serious, dose and treatment limiting effects
- "flu-like"
- depression
- suicidal ideations
84
What is the purpose of pegylating interferons?
- reduce daily dosing requirements
| - reduce ADRs
85
What are the second generation Hep C agents?
- Telaprevir
- Boceprevir
- Sofosbuvir
- Simeprevir
- Ledipasvir & Sofosbuvir
- Ombitasvir & Paritaorevir & Ritonavir + Dasabuvir
86
What class does telaprevir belong to?
protease inhibitor
87
Telaprevir targets Hep C genotype __.
1
88
Which is the most difficult Hep C genotype to treat?
1
89
Telaprevir is intended to be used with what other medications?
- peg-interferon α
| - ribavirin
90
What is the dosage of telaprevir?
- 375 mg (3 tabs) BID with food ( ≥ 20 g of fat)
91
What are ADRs of telaprevir?
- rash (SJS?)
- anemia
- NV
- dysphagia
- anal irritation
92
What class does boceprevir belong to?
protease inhibitor
93
Boceprevir targets Hep C genotype __.
1
94
What is the dosage of Boceprevir?
800 mg PO TID
95
Boceprevir is intended to be used with what other medications?
- peg-interferon α
| - ribavirin
96
What are the ADRs of boceprevir?
- fatigue
- anemia
- headache
- dysphagia
- alopecia
97
What class does Sofosbuvir belong to?
polymerase inhibitor
98
Sofosbuvir is effective against Hep C genotypes __ - __.
1 - 6
99
What is the dosage of sofosbuvir?
400 mg PO QD with or without food
100
What is the regimen for Hep C G1 and G4?
12 weeks of triple therapy : sofosbuvir + interferon + ribavirin
101
What is the regimen for Hep C G2?
12 weeks of dual therapy : sofosbuvir + ribavirin
102
What is the regimen for Hep C G3?
24 weeks of dual therapy : sofosbuvir + ribavirin
103
What are the common ADRs of sofosbuvir?
- fatigue
| - headache
104
What class does simeprevir belong to?
Hep C specific protease inhibitor
105
What Hep C genotype is simeprevir effective against?
genotype 1
106
What is the dose of simeprevir?
150 mg PO QD with food
107
What medications must simeprevir be used with?
interferon + ribavirin
108
What are common ADRs of simeprevir?
- rash
- photosensitivity
- nausea
- pruritus
- myalgia
109
What medications make up Harvoni?
- ledipasvir
| - sofosbuvir
110
What is the MOA of ledipasvir?
inhibits viral phosphoprotein NS5A
111
What is the MOA of sofosbuvir?
polymerase inhibitor (mimics uridine analogs)
112
What is the dose of Harvoni?
1 tablet PO QD on empty stomach
113
What Hep C genotype does Harvoni target?
genotype 1
114
What is the range of duration of therapy of Harvoni?
8 - 24 weeks
115
What category of medication should be avoided with Harvoni?
stomach acid reducers
116
What is the MOA of ombitasvir?
inhibits HCV NS5A protein
117
What is the MOA of paritaprevir?
inhibits HCV NS#/4A protease
118
What is the MOA of ritonavir?
inhibits CYP3a (favorable drug interaction)
119
Ritonavir has no Hep C activity. (T/F)
True
120
What is the MOA of Dasabuvir?
inhibits NS5B RNA-dependent polymerase
121
What Hep C genotype does Viekira Pak target?
G1
122
What antivirals are used to treat influenza?
- Amantidine
| - Rimantidine
123
What is the MOA of Amantidine?
inhibits viral M2 protein with resultant blockage of viral replication
124
What is the relationship of rimantidine to amantidine?
hydrophilic analog of amantidine with reduced CNS ADRs
125
Amantidine is used for what other condition?
dopamine agonist used to manage Parkinson's disease
126
There is high incidence of resistance to amantidine. (T/F)
True
127
In what patient population are amantidine and rimantidine indicated in?
high-risk individuals who are not candidates for vaccinations
128
Neuraminidase inhibitors are derivatives of what?
amantidine
129
What is the MOA of neuraminidase inhibitors?
inhibits viral neuraminidase: enzyme critical in the maturation and infectivity of newly produced viral particles
130
What strains of influenza is neuraminidase inhibitor effective against?
A and B
131
Neuraminidase inhibitors are most effective when administered within ____ of symptom onset and no more than ___.
- 30 hours
| - 48 hours
132
What are the neuraminidase inhibitor agents?
- Zanamivir
- Oseltamivir
- Peramivir
133
What is the route of administration of zanamivir?
inhaled powder
134
What is the route of administration of oseltamivir?
oral
135
What is the route of administration of peramivir?
parenteral
