Chapter 20: Antibacterial Drugs - Antiprotozoan + Antiviral Agents

Question 1

What problems arise for antiprotozoan agents? (2)

Answer 1

• toxicity because there are few major differences between human cells and protozoa
• very few drugs available, and it is usually specific for one protozoan

Question 2

Name 2 antiprotozoan agents

Answer 2

• Quinine
• Metronidiazole

Question 3

What is quinine used to treat and how?

Answer 3

• malaria
• interferes with DNA replication

Question 4

What is metronidiazole (Flagyl) used to treat? (2)

Answer 4

• Giardia lamblia (beaver fever)
• also used against some anaerobic bacteria and yeasts

Question 5

How does metronidiazole work?

Answer 5

inhibits fermentation (anaerobic metabolism)

Question 6

Worldwide, approximately how many infections are viral?

Answer 6

60%

Question 7

Are antiviral agents readily accessible? (2)

Answer 7

• very few antivirals are available
• most work against only one virus

Question 8

Name the 5 steps that antiviral agents do.

Answer 8

1. Prevent viral entry
2. intefere with uncoating
3. nucleoside analogues
4. Integrase inhibitors
5. Prevent assembly and release

Question 9

What examples are given in which an antiviral agent prevents viral entry? (2)

Answer 9

• marviroc blocks HIV host cell receptor
• Enfuvirtide blocks fusion by HIV

Question 10

What example is given in which an antiviral agent interferes with uncoating?

Answer 10

• amantadine and rimantadine blocks uncoating by influenza

Question 11

What occurs in nucleoside analogues?

Answer 11

• interfere with viral nucleic acid synthesis

Question 12

What examples are given in for nucleoside analogues? (2)

Answer 12

• acyclovir block replication by herpes viruses
• AZT blocks replication by HIV

Question 13

When are nucleoside analogues effective? (2)

Answer 13

• effective only against multiplying viruses
• cannot cure latent infections

Question 14

What is an integrase inhibitor?

Answer 14

• prevent virus from integrating its genone as a provirus

Question 15

What example is given for an integrase inhibitor?

Answer 15

• raltegravir blocks integration by HIV

Question 16

What occurs when an antiviral agent prevents assembly and release? Use the examples (2)

Answer 16

• protease inhibitors block HIV and hepatitis C from producing proteins
• Neuraminidase inhibitors block release of influenza viruses