Intro To AntiVirals

Question 1

Describe early phase of viral infection

And late phase

Answer 1

1 attachment and entry
2 uncoating
3 replication of viral DNA

4 replication of viral proteins
5 assembly of viral particles
6 release of virus and rupture of cell

Question 2

Describe graph of viral infection

Answer 2

1 after entry number reduces
2 virus enter eclipse period ( asymptotic) inside cell
3 virus begin replication and increase exponentially
4 enter latent period ( active in ecm ) and increase exponentially

Question 3

Major problem of viral infections

Answer 3

/they are asymptomatic and when signs start showing the disease has already established itself

Question 4

What do antivirals do

Answer 4

-target steps of viral replication and not the virus itself

Question 5

List examples of DNA virus infections and retrovirus ones

Answer 5

1 chicken and small pox , hepatitis B, cold sore

2 cold , measles , rubella , mumps , hepatitis A , AIDS , influenza

Question 6

List the stages attacked by antivirals

Answer 6

1 viral attachment 
2 penetration 
3 uncoating
4 early protein synthesis 
5 nucleic acid synthesis 
6 late protein synthesis
7 packing and assembly

Question 7

Example of antivirals that attack attachment stage and the viruses they prevent

Answer 7

Maraviroc ( HIV )
Docosanol ( HSV )
Palivizumab ( RSV )

Question 8

Example of antivirals that attack penetration stage and the viruses they prevent

Answer 8

Interferon Alfa ( injectable agents )
HBV
HCV

Question 9

Example of antivirals that attack coating stage and the viruses they prevent

Answer 9

Amantadine ( influenza )

Question 10

Example of antivirals that attack nucleic acid synthesis stage and the viruses they prevent

Answer 10

NRTI ( HIV )
Acyclovir ( HSV )
Foscanet ( CMV )

Question 11

Example of antivirals that attack late protein synthesis stage and the viruses they prevent

Answer 11

Protease inhibitors- HIV

Question 12

Example of antivirals that attack packing and assembly stage and the viruses they prevent

Answer 12

Neuraminidase - influenza

Question 13

Why do antivirals sometimes fail

Answer 13

• resistance of virus
• toxicity of drug
• regimen complications

Question 14

List agents against Herpes

Answer 14

1 acyclovir

• valacyclovir
• foscarnet
• brivudin
• pencicyclovir

Question 15

What does acyclovir fight and how is it activated for action

It’s mode of action and side effects

Answer 15

• against HSV 1,2 and VZV
• it has to be phosphorylated and this occurs through viral enzyme thymidine kinase
• inhibits viral DNA synthesis via competitive inhibition of herpesvirus DNA polymerase
• incorporating into viral DNA ( viral DNA chain termination )

-few tolerable side effects such as nausea , diarrhea and headache

Question 16

What does Cytomegalovirus do and drugs of choice

Answer 16

• causes end organ damage

- gancicyclovir , foscarnet or cidofovir

Question 17

Meaning of OD , OD HS , BD and TDS

Answer 17

/once daily

• once daily at night
• twice a day
• three times a day

Question 18

Example of anti hepatitis drug and what they do

Answer 18

• lamivudine

- more suppressive than curative

Question 19

Side effects of anti influenza drugs

Answer 19

/nausea , abdominal pain due to gastric irritation , headache , insomnia and sadness

Question 20

Types of anti influenza drugs ( a mental disease they can also cure ) and criteria for choice

Mode of action

Answer 20

• choice depend on strain
• amantidine , zanamivir , rimatadine

/Parkinson’s disease

-inhibit uncoating of viral agents