antiviral (not HIV and hepatitis) Flashcards Preview

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Flashcards in antiviral (not HIV and hepatitis) Deck (40):
1

antiviral therapy (except HIV) - only the groups according their action

1. protein synthesis inhibitors
2. Uncoating agents
3. nucleic acid synthesis inhibitors
4 release of progeny virus inhibitors

2

release of progeny virus inhibitors - agents and mechanism of action

1. Oseltamivir
2. zanamivir
inhibit influenza neuraminidase

3

release of progeny virus inhibitors - clinical use

treatment and PREVENTION of both infleunza A and B

4

nucleic acid synthesis inhibitors - groups and agents

1. Guanosine analogs: Acyclovir, famciclovir, valacyclovir, ganciclovir
2. viral DNA polymerase inhibitors: Cidofovir, foscarnet
3. Guanine nucleotide synthesis inhibitos: Ribavirin

5

nucleic acid synthesis inhibitors - Guanosine analogs - drugs

1. Acyclovir
2. famciclovir
3. valacyclovir
4. ganciclovir

6

Acyclovir, famciclovir, valacyclovir - mechanism of action

guanosine analog --> Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells (few adverse effects) --> Triphosphate formed by cellular enzymes --> preferentially inhibit viral DNA polymerase by chain termination

7

Acyclovir, famciclovir, valacyclovir - active against

1. HSV
2. VZV
3. EBV (weak)
NOT CMV

8

Acyclovir, famciclovir, valacyclovir - clinical use

1. HSV-induced mucocutaneous lesion (hepres)
2. HSV-induced genital lesion (hepres)
3. HSV-encephalitis
4. prophylaxis in immunocompromised
5. Hairy cell leukoplakia
6. hepres zoster (famciclovir)
NO EFFECT ON LATENT STATE

9

Herpes zoster - treatment

famciclovir

10

Acyclovir vs valacyclovir according to bioavailability

Valaciclovir is a prodrug of acyclovir --> better oral bioavailability

11

Acyclovir, famciclovir, valacyclovir - toxicity

1. obstructive cystalline neuropathy
2. acute renaL failure if not adequately hydrated

12

Acyclovir, famciclovir, valacyclovir - resistance

Mutated viral thimidine kinase

13

Ganciclovir - mechanism of action

5-Monophosphated formed by CMV viral kinase --> Triphosphate formed by cellular enzymes --> preferentially inhibits viral DNA polymerase by chain termination

14

Ganciclovir - clinical use

CMV, especially in immunocomprommised patients

15

Ganciclovir - oral

Valganciclovir, a prodrug of ganciclovir --> better oral bioavailability

16

acyclovir and ganciclovir - oral

- Valaciclovir is a prodrug of acyclovir --> better oral bioavailability
- Valganciclovir, a prodrug of ganciclovir --> better oral bioavailability

17

ganciclovir - toxicity

1. leukopenia
2. neutropenia
3. thrombocytopenia
4. Renal toxicity

18

ganciclovir vs acyclovir according to toxicity on host cells

ganciclovir is more toxic to host enzymes than acyclovir

19

ganciclovir - resistance

mutated viral kinase

20

nucleic acid synthesis inhibitors - Guanosine analogs - drugs

1. Acyclovir
2. famciclovir
3. valacyclovir
4. ganciclovir

21

viral DNA polymerase inhibitors - drugs

1. Cidofovir
2. foscarnet

22

Foscarnet - mechanism of action

Viral DNA/RNA polymerase inhibitor and HIV reverse transcriptase inhibitor. Binds to pyrophophate-binding site of enzyme. Does not require activation of viral kinase (PYROPHOSPHATE ANALOG)

23

Foscarnet inhibits

1. Viral DNA/RNA polymerase
2. HIV reverse transcriptase

24

Foscarnet - clinical use

1. CMV retinitis in immunocomporomised patients when gancyclovir fails
2. Acyclovir resistant HSV

25

Foscarnet - toxicity

1. nephrotoxicity
2. electrocyte abnormalities (hypo- hypercalcemia, hypo- hyperphosphatemia, hypokalemia, hypomagnesemia) --> can lead to seizures

26

Foscarnet - mechanism of resistance

Mutated DNA polymerase

27

viral DNA polymerase inhibitors - drugs

1. Cidofovir
2. foscarnet

28

Cidofovir - mechanism of action

Preferentially inhibits viral DNA polymerase. Does not require phosphoryation by viral kinase. LONG HALF LIVE

29

Cidofovir - clinical use

1. CMV retinitis in immunocompromised patients
2. Acyclovir-resistant HSV

30

cidofovir vs foscarnet according to half live

Cidofovir has LONG HALF LIVE

31

Cidofovir - toxicity

nephrotoxicity

32

Cidofovir - toxicity - solution

coadminister with probenecid and IV saline to decrease toxicity

33

antiviral therapy (except HIV) - only the groups according their action

1. protein synthesis inhibitors
2. Uncoating agents
3. nucleic acid synthesis inhibitors
4 release of progeny virus inhibitors

34

antiviral - protein synthesis inhibitors - drugs

interderon-a

35

interderon - α - mechanism of action as an antiviral

protein synthesis inhibitors

36

Interferons as antivirals / types

Glycoproteins normaly synthesized by virus-infected cells, exhibiting a wide range of antiviral and antitumoral properties
α, β, γ interferons

37

interferons - clinical use

Interferons - α: 1. chronic hepatitis B, C 2. Kaposi sarcoma 3. hairy cell leukemia 4. condyloma acuminatum 5. renal cell carcinoma 6. malignant melanoma
Interferons - β: multiple sclerosis
Interferons - γ: chronic granulomatous disease

38

interferons - side effects

1. neutropenia
2. myopathy
3. Flu-like symptoms
4. depression

39

antiviral therapy - uncoating agents - drugs - clinical use

1. Amantadine
2. Rimantadine
no longer useful for influenza due to increased resistance

40

amantadine - clinical use and side effect

clinical use: 1. antiviral (rubella, infl A) 2. Parkinson
side effects: 1. ataxia 2. livedo reticularis