CP3-2 antivirals

Question 1

What are the two types of influenza virus that cause flu in humans?

Answer 1

Influenza A
Influenza B

Question 2

What are the subtypes of influenza A?

Answer 2

A(H1N1)
A(H3N2)

Question 3

What are the 2 lineages of influenza B?

Answer 3

B(Victoria)
B(Yamagata)

Question 4

How are individuals with influenza treated if they are not hospitalised or in an at risk group?

Answer 4

No treatment

Question 5

Who is classed as at risk of complicated influenza?

Answer 5

Those with chronic diseases affecting neurological, hepatic, renal, pulmonary or cardiac systems
Those with diabetes mellitus
Those with severe immunosuppression
Those aged over 65
Pregnant women (and up to 2 weeks post partum) especially if they have a BMI >40

Question 6

What is used to treat influenza in those who need medication?

Answer 6

Oseltamivir (Tamiflu) - a neuraminidase inhibitor
Amantadine- a M2 proton channel blocker

Question 7

What type of influenza does amantadine treat?

Answer 7

Type A only

Question 8

Why is amantadine not used any more?

Answer 8

Due to high resistance to it

Question 9

How effective is oseltamivir?

Answer 9

If given early, shortens duration of symptoms and reduces complications. Reduces death in hospitalised adults and shortens duration of hospital stay for children.

Question 10

What herpes viruses have active antivirals?

Answer 10

HSV1 and 2
Varicella zoster virus (VZV)
Cytomegaly virus (CMV)

Question 11

What antiviral are HSV1 & 2 and VSV susceptible to?

Answer 11

Acyclovir

Question 12

Which HSV1&2 manifestations require treatment with acyclovir?

Answer 12

Genital or encephalitis
(Not oral or meningitis)

Question 13

Which VSV manifestations require treatment with acyclovir?

Answer 13

Chicken pox in adults and shingles in those >60, the immunocompromised and/or if the eyes are involved

Question 14

What is the mechanism of action of aciclovir?

Answer 14

It is a nucleoside analogue which uses the viral DNA polymerase inhibitor to terminate the chain in replication by replacing guanosine.

Question 15

What mechanisms of resistance affect the action of aciclovir?

Answer 15

Mutations in viral thymidine kinase no longer phosphorylate aciclovir preventing the drug from working.

Mutations in DNA polymerase reduces recognition of phosphorylated aciclovir as a substrate

Question 16

How does CMV manifest in the immunocompetent? Do we treat it?

Answer 16

Asymptomatic or mononucleosis with prolonged fever and hepatitis
No

Question 17

How does CMV manifest in the immunosuppressed?

Answer 17

As GI disease or pneumonitis or hepatitis or nephritis or retinitis

Question 18

What drugs treat CMV?

Answer 18

Ganciclovir (a nucleoside analogue)
Cidofovir (a monphosphate nuceloside analogue)

Question 19

What treatment of CMV is most likely to be affected by drug resistance?

Answer 19

Ganciclovir

Question 20

What drug is used to treat HIV?

Answer 20

AZT aka zidovudine

Question 21

What is the mechanism of action of zidovudine?

Answer 21

Nucleoside analogue - nuceloside reverse transcriptase inhibitor terminates DNA production as used in the place of thymidine.

Question 22

What is a disadvantage of only using AZT as treatment for HIV?

Answer 22

Using only one drug means resistance is likely to develop

Question 23

What is used in conjunction with AZT to treat HIV and AIDS?

Answer 23

Saquinavir and ddC

Question 24

What is the mechanism of action of saquinavir?

Answer 24

Protease inhibitor

Question 25

What it the triple therapy used to treat HIV?

Answer 25

HAART

Question 26

What is the most common treatment of HIV?

Answer 26

2x NRTI drugs and 1x NNRTI/PI/INI

Question 27

What are the three mechanisms of actions of the drugs which can be used to treat HIV?

Answer 27

Protease inhibitors (prevent cleavage of protein precursors preventing production of new virons)

Non-nucleotide reverse transcriptase inhibitors (directly bind to reverse transcriptase stopping it functioning)

Integrate inhibitors (binds to inter grade preventing viral DNA inserting into the host genome)

Question 28

How is dual therapy for HIV administered?

Answer 28

Either orally or intramuscularly

Question 29

Who is treated for HIV infection?

Answer 29

Everyone infected irrespective of CD4 count

Question 30

What is the aim of HIV treatment?

Answer 30

Viral suppression to prevent CD4 levels declining and progression of disease

Question 31

Why are some NRTIs effective for HBV infection?

Answer 31

As reverse transcriptase is involved in the life cycle of HBV

Question 32

What are the drugs in use for treating HBV?

Answer 32

Entecavir
Tenofovir D
Tenofovir alafenamide

Question 33

What makes an effective antiviral?

Answer 33

High potency to the virus and genetic barriers to resistance.

Question 34

Who is treated for HBV infection?

Answer 34

Those infected with developing liver fibrosis

Question 35

How is it determined whether someone is at risk of developing liver fibrosis?

Answer 35

By ALT levels, eAg/eAb status, DNA, FibroScan estimation of liver fibrosis and age

Question 36

What are the mechanism of actions of Hep C virus drugs?

Answer 36

Protease inhibitor
Polymerase inhibitors
Replication complex inhibitors

Question 37

What non-panegenotypic drugs are used to treat HCV?

Answer 37

Zepatier (elbasvir and grazoprevir)
Harvoni (ledipasvir and sofosbuvir)

Question 38

What pangenotypic drugs are used to treat HCV?

Answer 38

Maviret (gleceprevir and pibrentasvir)
Epclusa (sofosbuvir and velpatasvir)

Question 39

What is the aim of HCV treatment?

Answer 39

To cure

Question 40

How long does HCV treatment usually take?

Answer 40

12 weeks

Question 41

Who is offered HCV treatment?

Answer 41

Everyone with HCV infection