Theme 3 Lecture 14: Antivirals

Question 1

What are the two types of viral infections?

Answer 1

1. acute (RNA) viruses
   - influenza, measles, mumps, hepA
2. Chronic (generally DNA) viruses
   - latent with (or without) recurrences- herpes simplex, cytomegalovirus
   - persistent - HIV, HepB, HepC

Question 2

Non-vesicular rashes are a symptom of which viruses?

Answer 2

• measles
• rubella
• parvovirus
• adenovirus
• HHV6

Question 3

Vesicular rashes are a symptom of which viruses?

Answer 3

• chicken pox
• herpes simplex 1&2
• enteroviruses

Question 4

What is a vesicular rash?

Answer 4

start off as red and raised but then become fluid filled

Question 5

When do we use antivirals?

Answer 5

• for acute infections in general population where there is a high risk of complication
• chronic infections
• infections in the immunocompromised

Question 6

Which antiviral do we use to treat herpes simplex?

Answer 6

acyclovir

Question 7

How do we treat chicken pox and shingles?

Answer 7

acyclovir

Question 8

Which patients with chicken pox and shingles would you treat with acyclovir?

Answer 8

-treat all adults with chicken pox
treat shingles with acyclovir if:
->60 
-involves eye
-immunocompromised

Question 9

Which patients do we treat for influenza?

Answer 9

• systemic disease
• diabetes
• severe immunosuppression
• age over 65 years
• pregnancy
• children under 6 months
• morbid obesity

Question 10

How do we treat influenza?

Answer 10

neuraminidase inhibitors oseltamivir (oral) and zanamivir (inhaled)

Question 11

Explain the 8 stages of virus replication

Answer 11

1. virus attachment to cell (via receptor)
2. cell entry
3. virus uncoating
4. early proteins produced - viral enzymes
5. replication
6. late transcription/translation
7. virus assembly
8. virus release and maturation

Question 12

What are NRTIs and what do they do?

Answer 12

• nucleoside reverse transcriptase inhibitors

- inhibit reverse transcriptase

Question 13

What is AZT and what is it used for?

Answer 13

• azidothymidine (AZT)
• developed as an anti-cancer drug
• found to inhibit HIV replication
• NRTI

Question 14

What are the HIV NRTIs?

Answer 14

1. pyrimidine analogues
   - thymidine analogues e.g zidovudine
   - cytosine analogues e.g iamivudine
2. purine analogues
   - abacavir
   - tenofovir

Question 15

What is aciclovir used to treat?

Answer 15

HSV and VSV

Question 16

What is ganciclovir used to treat?

Answer 16

CMV, HHV6 (as well as HSV and VSV)

Question 17

What is the treatment for hepatitis C virus?

Answer 17

RNA polymerase nucleotide inhibitor called sofosbuvir

Question 18

what are NNRTIs? (give two examples)

Answer 18

• non-nucleotide reverse transcription inhibitors

- examples are efavirenz and nevirapine

Question 19

What are examples of protease inhibitors that treat HIV?

Answer 19

• atazanavir
• darunavir
• ritonavir

Question 20

What are examples of protease inhibitors that treat HCV?

Answer 20

• paritaprevir

- grazoprevir

Question 21

What is HAART?

Answer 21

• highly active antiretroviral therapy
• 2 NRTIs + NNRTI
• drug combinations
• aim to switch off virus replication

Question 22

How do we treat HCV

Answer 22

generally use combination therapy (2 or 3 agents) for 8-12 weeks

Question 23

How do antivirals work?

Answer 23

• by blocking a particular stage of viral replication

- they act on unique viral proteins that are essential for replication; these usually act within a cell

Question 24

why is HepC an unusual virus?

Answer 24

• it is an RNA virus that can cause chronic infection
• it is the only chronic virus that, with antivirals, a cure can be achieved and the antivirals don’t have to be given life long