Antivirals

Question 1

What is an anti-viral agent

Answer 1

Medication which can fight off certain viruses
Can also be a preventative measure

Question 2

How does a Virus work?

Answer 2

1 - Pathogen enters host cell
○ Attaches to host cell viral receptor
○ Causes release of viral genes and enzymes into the host cell
2- Inside the cell viral components are replicated by reverse transcriptase
○ Viral DNA is able to enter host cell nucleus
○ Incorporated into cell using the host cells machinery
○ Brings about assembly of viral components (transcription and translation)
3 - Viral particles exit into the cytoplasm and then leave the cell via exocytosis going on to infect new host cells
4 - The use of host cells to replicate makes it challenging to develop antiviral medicines
5 - General idea is to identify viral proteins on a cell surface and disable them
6 - To increase effectiveness of an antiviral the target protein should be common to multiple viral strains
Similar cell surface proteins

Question 3

what are the methods of anti-viral treatment?

Answer 3

‘viral enzyme inhibition’
○ Blocks viral entry so can’t replicate
‘immune response enhancement’
○ Blocks ability of virus to attach/enter host cells

Question 4

Acyclovir Action

Answer 4

Becomes incorporated into viral DNA leading to viral DNA chain being terminated

Relatively safe

Question 5

Acyclovir Uses

Answer 5

○ Useful against a variety of viruses (mainly DNA viruses)
Herpesvirus family
E.g. Pacheco’s disease (parrots / cockatoos)

Question 6

Acyclovir administration options

Answer 6

Opthalmic ointment
Topical ointment
IV preparations
Oral formulations

Question 7

Famciclovir action

Answer 7

Positive effect on reducing respiratory and occcular clinical signs of FHV-1

Longer duration of action

Question 8

Famciclovir uses

Answer 8

Herpesvirus family (cats)

Question 9

Trifluridine Action and uses

Answer 9

Anti-herpes drug
primarily occular herpes

Question 10

Zidovudine action

Answer 10

Enters viral infected cell and prevents replication in early stage

Question 11

Zidovudine uses

Answer 11

Useful in acte stages
Retroviruses – FeLV & FIV

Question 12

Ribavarin uses

Answer 12

Broad spectrum
Adenoviruses
Herpesviruses
Rotaviruses
Retroviruses

Question 13

Ribavarin complications

Answer 13

Weight loss
Anaemia
Bone marrow depression

Question 14

Anti-viral meaning

Answer 14

A drug used to treat infections caused by viruses

Question 15

Viricide meaning

Answer 15

Destroys or inactivates viral particulates outside of the body
Used in environment - not a medication