Antiviral Drugs Flashcards
What patient populations are of the highest risk of fatality due to viral infections?
Immune compromised and age (neonate and elderly)
What do viruses require for replication?
A living host cell
*they are obligate intracellular parasites
T/F viruses are highly antigenic due to envelope and capsid proteins
True
What part of viruses do antiviral drugs target?
Nucleic acids, enzymes and capsid proteins
What is the cycle of an active viral infection?
- Virus attaches to host cell (usually a specific cell)
- Viral genetic material enters that cell
- Viral DNA or RNA takes control of the cell
- Uses hosts cell to synthesize viral proteins and nucleic acids
- New viruses are assembled in cytoplasm of cell
- Viruses released by lysis of host cell or by budding from host cell membrane
What parts of the active virus cycle can antiviral drugs target?
- Attachment and entry
- RNA/DNA synthesis
- DNA incorporation
- Protein synthesis
- Release
What is the structure of herpesviridae viruses?
Double stranded DNA virus
Is there a vaccine for herpesviridae viruses?
No, only antiviral medications
Where do herpesviridae viruses stay dormant?
Lymphatic or sensory nervous system
What is the difference between a canker sore and a cold sore?
- Canker sores are NON-infectious, NON-contagious, singular lesions on the inner mucosa. TX is pain control
- Cold sores are infectious, highly contagious, dormant, multiple lesions on the inner and out mucosa. TX is antiviral drugs and pain control
What causes a cold sore?
HSV (herpes simplex virus)
What causes a canker sore?
Triggers (citrus, stress, etc)
What is a specific treatment for a cold sore and what is its MOA?
Docosanol (abreva)
-Blocks viral attachment - inhibits viral entry into the host cell by interfering with fusion of the envelope with the cell membrane
What are three HSV antiviral drugs?
- Acyclovir (and valcyclovir)
- Famciclorvir
- Penciclovir
What is the MOA of acyclovir?
- False guanosine metabolite
- Inhibits viral DNA synthesis (false base)
- It binds to DNA to form an irreversible complex with Viral DNA Polymerase
What forms does acyclovir come in?
PO, IV and topical
What type of drug is acyclovir?
Prodrug (must be metabolized to its active state)
What are some uses of acyclovir?
Genital herpes, herpes encephalitis, varicella, zoster
What is the bioavailability of acyclovir?
<30% oral bioavailability
How can we increase the bioavailability of acyclovir?
Valcyclovir - prodrug that gets converted to acyclovir
- the valine increases the oral bioavailability
- PO only