Antivirals Flashcards
Exam 4
Instead of being alive or dead, viruses are what?
Active or inactive
Define how viruses are considered obligate intracellular parasites
- Cannot multiply unless they invade a specific host cell
- Must instruct the genetic and metabolic machinery of the host cell to make and release new viruses
Viruses are considered ______ instead of organisms
infectious particles
Differentiate between lysogenic vs lytic viral cycles
Lysogenic - slow release; prolonged (years to decades)
Lytic - burst host cell; acute/self-limiting infection (24-hour stomach bug)
Plants have ______ viruses than animals
More
Viruses lack _______-synthesizing machinery
protein
Viruses vs bacteria nucleic acids
Viruses - DNA or RNA (ss or ds)
Bacteria - DNA only
What 2 parts do viruses have that are required to invade and control a host cell?
- External coating (capsid)
- Core containing nucleic acids
What are the 3 classes of viruses?
DNA, RNA, and retroviruses
Are retroviruses DNA or RNA based?
RNA
What is the only retrovirus?
HIV
What enzyme are retroviruses named after?
reverse transcriptase
A _______ is the protein shell that surrounds the nucleic acid
Capsid
A naked virus only consists of a ______
nucleocapsid
_______ is a capsid and nucleic acid together
Nucleocapsid
_______ allow viruses to dock with their host cells
Spikes
The _______ is usually a modified piece of the host cell membrane
Envelope
A _______ is a fully formed virus able to establish infection in a host
Virion
A virus family has the suffix _____
-viridae
A virus genera has the suffix _____
-virus
What are the 5 steps of viral replication?
- Absorption
- Penetration
- Synthesis
- Maturation
- Release
______ is the step of viral replication where the virus attaches to the host cell via a matching viral spike
absorption
______ is the step of viral replication where virions enter into host cells
penetration
_____ is the type of viral penetration that includes the entire virus entering the cell
uncoating
What is synthesized during the synthesis phase of viral replication?
new nucleic acids, capsid proteins, and other viral components
______ is the step of viral replication where the assembly of newly synthesized viral components into complete virions
maturation
______ is the step of viral replication where virions leave the host cells
release
What are the 3 viral infections that only occur in certain regions?
Dengue fever, Rift Valley fever, Yellow fever
Antivirals have only been available since the late _____
1970s
It is difficult to design therapies against viruses because they ___________
mutate at a rapid rate
Which drug is considered the prototype for antiviral drugs that inhibit viral DNA synthesis?
Acyclovir
What does acyclovir look similar to? What is the difference?
the normal nucleotide bases - missing hydroxyl group
When viruses mistakes acyclovir for dGTP, _______ is irreversible
chain termination
Acyclovir _____ safe in pregnant women
is
What are the 3 indications for acyclovir therapy?
HSV1, HSV2, and VZV infections
HIV targets which cells?
T-cells - CD4+
What is the main drug used to treat HIV?
Zidovudine (Azidothymidine, AZT)
What is the MOA of Zidovudine (Azidothymidine, AZT)?
Inhibitor of reverse transcriptase
What is the drug combination therapy called to treat HIV?
Highly Active Antiretroviral Therapy (HAART)
What is the MOA of lamivudine?
Inhibits HBV DNA polymerase and HIV reverse transcriptase
What is the medication called that prevents HIV infections?
PrEP - Cabotegrovir (blocks integration)
What are the 2 main drugs used to treat HIV?
Zidovudine (Azidothymidine, AZT)
Lamivudine
The CDC recommends flu vaccine for who?
EVERYONE 6 months and older every year
Differentiate between Influenza Type A and Type B
A - Causes moderate to severe illness; Affects all age groups
B - Milder illness; Primarily has had an impact on adolescents and schoolchildren
Influenza subtypes are determined by what?
cell surface antigens hemagglutinin and neuraminidase
The cell surface antigen that has a role in virus attachment to cells is ________
hemagglutinin (H1, H2, H3)
The cell surface antigen that has a role in virus penetration to cells is ________
neuraminidases (N1, N2)
What are the 3 antivirals used to treat influenza?
Oseltamivir phosphate (Tamiflu)
Zanamivir (Relenza)
Baloxivir marboxil (Xofluza)
Xofluza may reduce the length of flu duration by about _____
a day
Which antiviral for the treatment of the flu must be taken when exposed?
Relenza
What is the contraindication for taking Relenza for the flu?
Not recommended for people with asthma or COPD
What is the contraindication for taking Xofluza for the flu?
Not recommended for pregnant women, breastfeeding mothers, outpatients with progressive or complicated illness, or hospitalized patients (not enough information available in these populations)
What are the 4 FDA-approved treatments for covid?
Paxlovid
Remdesivir
COVID mabs
Dexamethasone
What is the MOA of Remdesivir for treatment of covid?
chain terminator
What is the MOA of mabs for treatment of covid?
Block COVID entry into cells
What is the MOA of dexamethasone for treatment of covid?
cytokine suppression of cytokine storm
What is the name of the naturally occurring human cell product that can be used in preventing and treating viral infections?
Interferon (IFN)
What are the several known (4) coronaviruses that can cause respiratory infections in humans?
- Common cold
- Severe acute respiratory syndrome (SARS)
- Middle East respiratory syndrome (MERS)
- COVID-19
