Antiviral Agents: Classification, Mechanisms, and Resistance

Question 1

Which of the following is NOT classified as an antiviral agent?

Accepted Answer

Quinolone antibiotics

Answer

Nucleoside analogs

Answer

Non-nucleoside reverse transcriptase inhibitors

Answer

Protease inhibitors

Question 2

What is the primary mechanism of action of acyclovir?

Accepted Answer

Inhibits viral DNA polymerase

Answer

Inhibits viral RNA polymerase

Answer

Inhibits viral entry into host cells

Answer

Inhibits viral uncoating

Question 3

Which antiviral agent is indicated for the treatment of human immunodeficiency virus (HIV)?

Accepted Answer

Zidovudine

Answer

Amantadine

Answer

Acyclovir

Answer

Ribavirin

Question 4

Which of the following is classified as a non-nucleoside reverse transcriptase inhibitor?

Accepted Answer

Efavirenz

Answer

Tenofovir

Answer

Lamivudine

Answer

Saquinavir

Question 5

How do protease inhibitors primarily inhibit viral replication?

Accepted Answer

Block the maturation of viral particles

Answer

Prevent viral entry into host cells

Answer

Interfere with viral RNA synthesis

Answer

Inhibit viral DNA replication

Question 6

How does acyclovir exert its antiviral effect?

Accepted Answer

Acyclovir, a nucleoside analogue, is phosphorylated by viral thymidine kinase to its active form, which inhibits viral DNA polymerase.

Answer

Acyclovir, a non-nucleoside analogue, directly binds to viral DNA polymerase, preventing its activity.

Answer

Acyclovir inhibits viral RNA polymerase by binding to the viral RNA template, blocking RNA synthesis.

Answer

Acyclovir, a protease inhibitor, prevents the cleavage of viral proteins necessary for viral replication.

Question 7

Which of the following is NOT a commonly used mechanism of action for antiviral agents?

Accepted Answer

Stimulating the host's immune response

Answer

Inhibiting viral entry into host cells

Answer

Interfering with viral genome replication

Answer

Blocking viral protein synthesis

Question 8

Which of the following is the main target of acyclovir's antiviral activity?

Accepted Answer

Viral DNA polymerase

Answer

Viral RNA polymerase

Answer

Viral protease

Answer

Viral integrase

Question 9

Which of the following is an example of an entry inhibitor?

Accepted Answer

Maraviroc

Answer

Zidovudine

Answer

Darunavir

Answer

Acyclovir

Question 10

What is the primary role of reverse transcriptase inhibitors (RTIs) in antiviral therapy?

Accepted Answer

Inhibiting viral genome replication

Answer

Preventing viral entry into host cells

Answer

Blocking viral protein synthesis

Answer

Enhancing immune responses against the virus

Question 11

Which of the following is a type of nucleoside analogue?

Accepted Answer

Zidovudine

Answer

Foscarnet

Answer

Ribavirin

Answer

Enfuvirtide

Question 12

Which enzyme is the primary target of protease inhibitors?

Accepted Answer

Protease

Answer

Polymerase

Answer

Integrase

Answer

Reverse transcriptase

Question 13

Antiviral agents are specifically designed to target and inhibit the replication process of viruses.

Accepted Answer

True

Answer

False

Question 14

Which class of antiviral agents specifically targets the viral capsid?

Accepted Answer

Capsid inhibitors

Answer

Nucleoside and nucleotide analogues

Answer

Protease inhibitors

Answer

Neuraminidase inhibitors

Question 15

Which antiviral agent is primarily used in the treatment of HIV infections?

Accepted Answer

Zidovudine

Answer

Acyclovir

Answer

Ribavirin

Answer

Amantadine

Question 16

Which of the following viruses is classified as a retrovirus?

Accepted Answer

HIV

Answer

Herpes simplex virus

Answer

Influenza virus

Answer

Hepatitis B virus

Question 17

Which of the following is an example of a nucleoside analog?

Accepted Answer

Acyclovir

Answer

Amantadine

Answer

Oseltamivir

Answer

Foscarnet

Question 18

Which of the following is the primary target of amantadine?

Accepted Answer

Viral M2 protein

Answer

Viral RNA polymerase

Answer

Viral integrase

Answer

Viral protease

Question 19

Which characteristic is unique to non-nucleoside reverse transcriptase inhibitors?

Accepted Answer

Non-competitive with dNTPs

Answer

Bind to the polymerase active site

Answer

Competitive with dNTPs

Answer

Inhibit reverse transcriptase binding to the template

Question 20

Which of the following strategies do viruses use to evade the effects of antiviral agents?

Accepted Answer

Mutation of the target site

Accepted Answer

Reduced drug uptake

Accepted Answer

Increased drug efflux

Answer

Enhanced viral replication

Question 21

Explain the specific challenges in treating viral infections that affect different organ systems, such as the central nervous system or the liver, and discuss the underlying mechanisms responsible for these challenges.

Accepted Answer

For viral infections affecting the central nervous system, crossing the blood-brain barrier poses a significant challenge, while extensive hepatic metabolism can reduce drug efficacy for infections affecting the liver.

Answer

Viral infections in different organ systems generally respond similarly to antiviral agents, with no significant variations in treatment strategies.

Answer

Organ-specific challenges in treating viral infections solely affect the pharmacokinetics of antiviral agents, with no impact on their pharmacodynamics.

Question 22

Which of the following is NOT a target for antiviral drugs?

Accepted Answer

Host cell replication

Answer

Viral uncoating

Answer

Viral replication

Answer

Viral entry

Question 23

Acyclovir primarily acts by inhibiting:

Accepted Answer

Viral DNA polymerase

Answer

Viral protease

Answer

Viral reverse transcriptase

Question 24

Which class of antiviral agents prevents the fusion of the viral envelope with the host cell membrane?

Accepted Answer

Entry inhibitors

Answer

Protease inhibitors

Answer

Integrase inhibitors

Answer

Non-nucleoside reverse transcriptase inhibitors

Question 25

Which of the following is an example of a non-nucleoside reverse transcriptase inhibitor?

Accepted Answer

Nevirapine

Answer

Zidovudine

Answer

Lamivudine

Answer

Tenofovir