5.1 Antiviral Agents

Question 1

GIve examples of 3 DNA based viruses

Answer 1

Herpes simplex
Varicella-zoster
Epstein Barr Virus
Hepatitis B

Question 2

Give 3 examples of RNA based viruses

Answer 2

Influenza
HIV
Hepatitis C

Question 3

Describe Type A Influenza

Answer 3

Capable of infecting animals and humans

Responsible for large flu epidemics

Question 4

List 3 symptoms of Type A influenza

Answer 4

Aching
Coughing
Sneezing
High fever

Question 5

Describe Type B influenza

Answer 5

Only found in humans

Does not cause pandemics

Question 6

Give 3 symptoms of Type B influenza

Answer 6

Aching
Coughing
Sneezing
High fever

Question 7

Describe Type C influenza

Answer 7

Mild virus
Similar to a common cold
Cannot cause epidemics

Question 8

What is haemagglutinin?

Answer 8

Protein which binds virus to the cell that it is about to infect

Question 9

What is neuraminidase?

Answer 9

Enzyme which cleaves the human mucous membrane so the virus can be free in the respiratory tract

Question 10

Describe the replication process of the influenza virus

Answer 10

1. ) Virus attaches to a neuraminic acid on a membrane glycoprotein
2. ) The complex moves into the cell via endocytosis
3. ) ATP drives proton entry into the endosome which allows fusion of the viral membrane with the endosomal membrane
4. ) Protons enter the virus via an M2 ion channel. The pH within the virus breaks down the viral coat of the nucleocapsid
5. ) The RNA escapes out of the virus and is transcribed in the cell
6. ) A new virus forms and is exocytosed from the cell

Question 11

What is the active particle in the flu vaccine?

Answer 11

Small dose of haemagglutinin-body creates antibodies

Question 12

Give 2 examples of M2 channel blockers

Answer 12

Amantadine

Rimantadine

Question 13

How do M2 ion channel blockers protect against Influenza A?

Answer 13

Blocking M2 channels inhibits viral uncoating

Question 14

Why is Rimantadine preferred over Amantadine?

Answer 14

Amantadine has CNS side effects such as dizziness, confusion, insomnia and hallucinations

Question 15

Give 2 examples of Neuramidase Inhibitors

Answer 15

Zanamivir

Oseltamivir

Question 16

How do Neuraminidase inhibitors protect against influenza A and B?

Answer 16

As new virus cells leave the host cell they can become caught in glycoprotein residues. The enzyme neuraminidase breaks these bonds. The drugs competitively antagonise the neuraminidase binding sites so the viruses stay on the cell membrane

Question 17

How is Zanamavir given to a patient?

Answer 17

Via an aerosol

Question 18

How is Oseltamivir given to a patient?

Answer 18

Orally