Antiviral Drugs

Question 1

What are two types of virucidal treatments

Answer 1

1. Detergents

2. cryotherapy

Question 2

What is an immunomodulatory treatment?

Answer 2

alpha interferon

Question 3

What are the four types of antivirals used ?

Answer 3

• nucleoside analogs
• nonnucleosides
• protease inhibitors
• entry inhibitors

Question 4

Name a drug that affects viral entry and what disease it is used to treat

Answer 4

-Enfuvirtide - HIV

Question 5

Nucleic acid synthesis inhibitors are primarily used to treat which two diseases?

Answer 5

Herpes virus and HIV

Question 6

In treating HIV, what specifically is targeted , in concerining the assembly and release step ?

Answer 6

-Protease inhibitors

Question 7

Influenza virus is treatable with zanamivir and oseltamivir, which both target the same step of virus replication - what is their target?

Answer 7

Neuramindase - cleaves sialic acid and releases virions from cell surface

Question 8

What antiviral is used to affect the host’s intrinsic immunity and what viruses does it target?

Answer 8

• peg-interferon

- HCV, HBV

Question 9

what are two “broad spectrum” treatments for DNA viruses?

Answer 9

foscarnet=foscavir

cidfovir=vistide

Question 10

how does foscarnet/foscavir work? (to treat DNA viruses)

Answer 10

inhibit DNA polymerase

Question 11

what type of virus is foscarnet/foscavir effective against? (to treat DNA viruses)

Answer 11

all herpesvirus

Question 12

what are two negatives of using foscarnet/foscavir and cidofovir/vistide? (to treat DNA viruses)

Answer 12

can only be administered via IV

toxic to kidneys

Question 13

what viruses are cidofovir/vistide active against?

Answer 13

herpesvirus
adenovirus
papillomavirus
pox virus

Question 14

what are the current drug options for hep B?

Answer 14

Peglyated interferon alpha
Entecavir=baraclude
Tenoforvir disoproxil fumarate=viread

Question 15

who should be treated for Hep B?

Answer 15

People with chronic active HBV disease
People co infected with HCV and/or HIV
People with progressing to cirrhosis, liver failure or hepatocellular carcinoma

Question 16

what is the mechanism of action for the drugs treating influenza virus?

Answer 16

both are sialic acid analogs that inhibit viral neuraminidase causing the virion to stay attached to the cell and not be able to infect other cells

Question 17

who should be treated for the influenza?

Answer 17

severely ill people
children younger than 2
adults over 65
pregnant women
immunosuppressed people
anyone suspected to have influenza

Question 18

list characteristics about Ribavirin

Answer 18

“broad spectrum” for RNA viruses
approved against HCV and RSV
can be given orally, IV or aerosol

Question 19

what is the current treatment for hep C virus?

Answer 19

combination peg-interferon-alpha with ribavirin

Question 20

what is the treatment for hep C with peg-interferon alpha considered difficult and complicated?

Answer 20

can cause flu like symptoms, anemia, neutropenia, rashes, hair loss, depression…
people want to stop taking them

Question 21

AZT (old HIV treatment) is a nucleoside analog of..?

Answer 21

thymidine

Question 22

cidofovir/vistide (treatment for DNA viruses) is a nucleoside analog of…?

Answer 22

cytosine

Question 23

what are the 5 anti HIV drug classes?

Answer 23

1. entry inhibitor
2. nucleoside/tide RT inhibitor
3. non nucleosdie/tide RT inhibitor
4. integrase inhibitor
5. protease inhibitor

Question 24

what is cobicisat? (component of the new HIV treatment that can be taken in 1 pill)

Answer 24

it is liver enzyme enhancer

it boosts the other components in the treatment by preventing their break down in the liver

Question 25

Describe the specificity of antivirals?

Answer 25

Most only target functions of one virus

Question 26

Are most antivirals reversible or irreversible?

Answer 26

Reversible - competitive inhibitors

Question 27

What does it mean that a virus rebounds after viral therapy?

Answer 27

Virus replication can resume when drug is cleared, and so treatment may need to be lifelong

Question 28

Does resistance to an antiviral develop after treatment with the drug?

Answer 28

No - often exists before drug treatment

Question 29

What are four factors favoring the emergence of resistance strains?

Answer 29

• high rate of replication
• high mutation rate (RNA»DNA)
• high selective drug pressure - long term treatments
• immunosuppressed can’t clear viruses

Question 30

What are three ways we can counter resistance to antivirals?

Answer 30

1. alleviate immunosuppression in a treated person
2. combine drugs with different targets - need them to synergize
3. Target host functions

Question 31

What two infections, is the standard of care combining multiple synergistic treatments?

Answer 31

HCV and HIV

Question 32

In order to treat zoster with an antiviral, what is the protocol?

Answer 32

Treatment only works within 3 days of appearance of rash

Question 33

Acyclovir is a nucleoside analog of _____

Answer 33

Guanosine

Question 34

What is the effectivity of acyclovir?

Answer 34

HSV1=HSV2»>VZV

Question 35

What is the trade name of acyclovir?

Answer 35

zovirax

Question 36

What are some names of derivatives of acyclovir?

Answer 36

Valtrex, denavir, famvir

Question 37

What is acyclovir’s mechanism of action?

Answer 37

1. Enters cell
2. Phosphorylated by viral TK
   
   • Specific for infected cells with herpes only
3. Host kinases add 2nd & 3rd Phosphates
4. GTP is recognized by viral DNA polymerase and is added to viral DNA
5. No hydroxyl group left for further addition – chain terminator

Question 38

Ganciclovir is a nucleoside analog of ____

Answer 38

guanosine

Question 39

What is ganiclovir used to treat?

Answer 39

CMV

Question 40

What is the mechanism of ganciclovir?

Answer 40

Similar mechanism as acyclovir, except it can be incorporated into host genome as well - TOXIC

Question 41

Who should be treated with ganciclovir?

Answer 41

• BM and organ transplant patients
• immunosuppressed and people with active CMV
• CMV retinitis