CH5-S3 Antivirals

Question 1

Challenges of antiviral drug:

Answer 1

Difficulty in obtaining selective toxicity against viruses
Relatively ineffective
Some viruses become latent within cells (e.g. herpes viruses)
Emergence of drug-resistant viral mutants

Question 2

Suggest an antiviral drug that can be used to treat herpes zoster, genital herpes, and chickenpox. How it works?

Answer 2

Acyclovir. It is a nucleoside analog that inhibits the action of viral DNA polymerase and DNA replication of different herpesvirus.

Question 3

Cells infected by a virus often produce ___, which inhibits further spread of the infection.

Answer 3

interferon

Question 4

Cells infected by a virus often produce interferon, which _________.

Answer 4

inhibits further spread of the infection

Question 5

Suggest an antiviral drug that can be used to treat viral hepatitis infections.

Answer 5

Alpha-interferon-drug

Question 6

Antiviral for influenza virus:
______ - prevents uncoating
______ and ______ are neuraminidase inhibitors

Answer 6

Amantadine,
Zanamivir, oseltamivir

Question 7

Antiviral for HIV:
________ - first HIV drug
It is a modified base, and it is not able to be extended once it is incorporated by the reverse transcriptase into DNA
However, it has ________
_________
__________

Answer 7

Azido-deoxythymidine (AZT)
substantial side effects, short half-life and mutants resistant to AZT

Question 8

Antiviral for HIV:
Azido-deoxythymidine (AZT)
Reverse transcriptase (RT) - an enzyme used to term reverse transcription
Nucleoside RT inhibitor (NRTI) - inhibit DNA synthesis by the reverse transcriptase of HIV
Non-nucleoside RT inhibitor (NNRTI) - inhibits the synthesis of viral DNA
Inhibitor of integrase - integrase mediates the integration of the newly synthesized viral DNA into host cell DNA
Protease inhibitors - block proteolytic cleavage of protein precursors that are necessary for the production of infectious viral particles
CCR5 inhibitors - blocks the binding of HIV to CCR-5 and virus entry

Question 9

Highly active antiretroviral therapy (HAART) is ____________________________________________________________

Answer 9

co-administration of a combination of three or more drugs that inhibit HIV viral replication by several mechanisms (the propagation of a virus with resistance to a single agent becomes inhibited by the action of the other two agents)

Question 10

Goal of highly active antiretroviral therapy (HAART)

Answer 10

Reduce morbidity and mortality (AIDS and non-AIDS associated causes)
Improve the quality of life
Reduce plasma viral RNA load
Prevent transmission to others (sex partners, needle-sharing partners, mother to infant)
Prevent drug resistance
Improve immune function