Antivirals

Question 1

Describe the different types of the influenza virus. (4)

Answer 1

A - multiple host species, shows antigenic shift and drift (seasonal)
B - only in human, lower mortality
C - common cold-like.

Question 2

Describe the common complications of influenza and the result of these. (2)

Answer 2

Bronchitis, sinusitis, pneumonia

~75% of patients with complications get antibiotics, which will do nothing for them.

Question 3

Explain the drive to create antivirals. (6)

Answer 3

Medical need - to increase health
Economic need - decrease cost of long term treatment
Commercial market need - decrease time off work / school.

Question 4

Describe the structure of influenza A. (5)

Answer 4

RNA virus with lipid envelope. Outer capsid features neuraminidase, hemagglutinin, and M2 channels.

Question 5

Describe the purpose of M2 channels. (2)

Answer 5

Allow H+ entry to the cell, which is needed for replication.

Question 6

Describe the purpose of hemagglutinin. (2)

Answer 6

This adheres to respiratory cells to allow influenza to enter the cell.

Question 7

Describe the purpose of neuraminidase. (3)

Answer 7

The constant region despite variance.

Helps with the final release following budding, by dissolving the attachment that the virus has to the cell.

Question 8

Name two amantadanes. (2)

Answer 8

Amantadine

Rimantadine

Question 9

Describe how amantadanes act as antivirals. (2)

Answer 9

Blocks the M2 channel to prevent viral replication.

Question 10

What were amantadanes developed originally for, and how have viruses become resistant to them? (2)

Answer 10

Parkinson’s Disease.

Mutations in the M2 channel.

Question 11

Name two antivirals that target neuraminidase. (2)

What is the outcome of these drugs? (1)

Answer 11

Oseltamivir
Zanamavir
Causes viral aggregation at the cell surface.

Question 12

Describe the main disadvantage of the pharmacokinetics of Zanamavir, and how this is combatted. (3)

Answer 12

Acid degraded, so very low bioavailability when taken orally. Combatted by taking through dry powder inhalers, so remains in the sputum for 24h.

Question 13

Describe the pharmacokinetics of oseltamivir. (2)

Answer 13

Given as a pro-drug.

Has 80% bioavailability.

Question 14

Describe four situations when oseltamivir would be prescribed for influenza. (4)

Answer 14

Pregnancy
Immunocompromisation
Lung disease in primary care
Any presentation in secondary care

Question 15

Describe the human herpes virus. (4)

Answer 15

~150 species of DNA virus spreading across humans and animals.
Generally presents with a mild primary infection in humans, but can establish a latent infection and reactivate later.

Question 16

Name four viruses that are transmitted orally and present with the primary infection in childhood. (4)

Answer 16

Herpes simplex-1
Varicella-zoster
HHV-6
HHV-7

Question 17

Name two orally transmitted viruses that can present with the primary infection at any age. (3)

Answer 17

Epstein Barr Virus.

CMV (also genital)

Question 18

Name two viruses that can be genitally transmitted that commonly present with the primary infection in adolescence. (3)

Answer 18

HHV-8 (also oral)

Herpes simplex-2

Question 19

Describe how latency of viruses occurs. (2)

Describe the locations of hiding virus for three different examples. (6)

Answer 19

Viral genome integrated into human cells and persists. Sporadic reactivation (eg in Immunosuppression) allows infection of new hosts.
HSV 1/2 - neurones
VZV - dorsal root ganglia
EBV - B cells

Question 20

Describe the oncogenes properties of two different viruses. (5)

Answer 20

EBV - B cell lymphoma, Burkitts lymphoma, nasopharyngeal cancers.
HHV-8 - Kaposi’s sarcoma.
All viruses can cause hepatitis also.

Question 21

Name two nucleoside analogues targeting herpes viral DNA polymerase. (2)

Answer 21

Aciclovir

Ganciclovir

Question 22

Describe the nucleoside analogue that you would use to treat common viral infections. (6)

Answer 22

Aciclovir - HSV, VZV

Ganciclovir - CMV, EBV