Antivirals Flashcards Preview

Z Old Infection IGNORE > Antivirals > Flashcards

Flashcards in Antivirals Deck (52):
1

What type of drugs are anti-herpes virus drugs?

Nucleoside inhibitors of DNA polymerase

2

What type of molecules are anti-herpes virus drugs?

Purine or pyrimidine nucleoside analogues (guanosine)

3

Give 5 anti-herpes virus drugs

  1. Aciclovir
  2. Valaciclovir
  3. Ganciclovir
  4. Famciclovir
  5. Foscarnet

4

What is the mechanism of action of anti-herpes virus drugs?

They are converted to nucleoside triphosphate by viral and cellular kinases that are incorporated into viral DNA to decrease the rate of chain elongation, and so they are chain terminators

5

What is the antiviral spectrum of anti-herpes virus drugs?

  • Herpes simplex virus
  • Varicella zoster virus
  • CMV 

6

What is aciclovir used to treat?

  • HSV-1
  • HSV-2
  • VZV

7

What is the mechanism of action of aciclovir?

First phosphorylation step is carried by a specific viral enzyme, thymidylate kinase, which leads to chain termination, directly inhibiting DNA polymerase

8

How are some viruses resistant to aciclovir?

  • May lack thymidylate kinase (TK-)
  • Possess mutations in the TK gene
  • Mutations that prevent DNA polymerase from binding to acyclovir triphosphate

9

For what is aciclovir the treatment of choice?

  • Herpes simplex encephalitis
  • Varicella-zoster virus infections
  • Fever blisters
  • Genital herpes

10

How is aciclovir given when treating herpes simplex encephalitis?

IV

11

When is aciclovir given to treat VZV infections?

When the patient is >50 years old

12

What are fever blisters also known as?

Herpes labialis

13

How is aciclovir given when treating fever blisters?

Topically

14

How is aciclovir given when treating genital herpes?

  • Topical
  • Oral
  • IV

15

What happens when aciclovir is given to patients with renal failure?

It accumulates

16

Does aciclovir have action against CMV?

No

17

What are the oral analogues of aciclovir?

  • Valaciclovir
  • Famciclovir

18

What is ganciclovir the treatment of choice for?

CMV infections, and its associated conditions

19

What conditions are associated with CMV infection?

  • Retinitis
  • Pneumonia
  • Colitis
  • Pneumonitis

20

In whom are CMV infections treated with ganciclovir?

Patients with AIDS, or are immunocompromised

21

How is the mechanism of action of ganciclovir like aciclovir?

It must be activated by phosphorylation, the triphosphate form of GCV inhibits the viral DNA polymerase

22

How is the mechanism of action of ganciclovir unlike aciclovir?

Phosphorylation of GCV is catalysed by phosphotransferase enzymes, both cellular and viral, and therefore GCV is activated in uninfected cells as well as infected cells, unlike aciclovir, which can only be activated by virally encoded TK

23

In whom is ganciclovir given as prophylaxis?

Transplant patients

24

Is the oral bioavailability of ganciclovir high or low?

Low

25

What is the result of the low oral bioavailability of ganciclovir?

It must be given IV, or valganciclovir given (much higher oral bioavailability)

26

What is the mechanism of action of foscarnet?

Prevents addition of nucleoside triphosphate dNTP to viral DNA, limiting the extension of the viral DNA strand

27

Does foscarnet phosphorylate?

No

28

What is foscarnet active against?

  • HSV-1
  • HSV-2
  • CMV
  • HIV

29

Why is foscarnet active against HIV?

Because it inhibits HIV reverse transcriptase

30

What are the anti-retroviral drugs (HAART)?

  • Reverse transcriptase inhibitors (RTIs)I
  • Integrase inhibitors
  • Protease inhibitors
  • Viral entry inhibitors

31

What are the types of RTIs?

  • Nucleoside RTIS (NRTI)
  • Non-nucleoside RTIs (NNRTI)

32

How do NRTIs and NNRTIs differ?

NRTIs have less activity on the host DNA polymerase

33

Give 5 NRTIs

  • Zidovudine 
  • Didanosine
  • Zalcitabine
  • Zerit
  • Tenofovir

34

Give 3 NNRTIs

  • Nevirapine
  • Delaverdine
  • Efavirenz

35

What should NNRTIs not be used as?

Monotherapy

36

Why should NNRTIs not be used as monotherapy?

Because of resistant mutants

37

Give an example of a integrase inhibitor?

Raltegravir

38

Give 4 protease inhibitors

  • Indinavir
  • Saquinavir
  • Lopinavir
  • Aprenavir

39

Give two viral entry inhibitors?

  • Fuzeon
  •  Maraviroc

40

What is fuzeon active against?

gp41

41

What is maraviroc active against?

CCR5

42

What are the types of anti-influenza drugs?

  • Anti-influenza A drugs
  • Anti-influenza B drugs

43

What are the types of anti-influenza A drugs?

  • Inhibitors of early events
  •  Neuroaminidase inhibitors

44

What is the mechanism of action of anti-influenza A drugs that inhibit early events?

Adamantanes (M2 ion channel) inhibitors

45

Give two anti-influenza A drugs that are inhibitors of early events

  • Amantadine
  • Rimantadine

46

What type of drugs are anti-influenza B drugs?

Neuraminidase inhibitors

47

Give 2 neuraminidase inhibitors

  • Zanamavir
  • Oseltamavir

48

What is the trade name of zanamavir?

Relenza

49

What is the trade name of oseltamavir?

Tamiflu

50

Label this diagram

 

  • A - NS2
  •  B - Lipid bilayer
  • C - NA (Neurominidase)
  • D - HA (Hemagglutinin)
  • E - M2 (ion channel)
  • F - M1 (matrix protein)
  • G - NP (nucleocapsid)
  •  H - PB1, PB2, PA (transcriptase complex)

51

What is neuraminidase required for?

  • For the virus to escape the infected cell
  • To penetrate the mucus in the airway

52

What is the M2 ion channel important for?

Uncoating of the virus