antiviral (not HIV and hepatitis)

Question 1

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

Answer 1

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

Question 2

release of progeny virus inhibitors - agents and mechanism of action

Answer 2

1. Oseltamivir
2. zanamivir
   inhibit influenza neuraminidase

Question 3

release of progeny virus inhibitors - clinical use

Answer 3

treatment and PREVENTION of both infleunza A and B

Question 4

nucleic acid synthesis inhibitors - groups and agents

Answer 4

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

Question 5

nucleic acid synthesis inhibitors - Guanosine analogs - drugs

Answer 5

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

Question 6

Acyclovir, famciclovir, valacyclovir - mechanism of action

Answer 6

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

Question 7

Acyclovir, famciclovir, valacyclovir - active against

Answer 7

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

Question 8

Acyclovir, famciclovir, valacyclovir - clinical use

Answer 8

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

Question 9

Herpes zoster - treatment

Answer 9

famciclovir

Question 10

Acyclovir vs valacyclovir according to bioavailability

Answer 10

Valaciclovir is a prodrug of acyclovir –> better oral bioavailability

Question 11

Acyclovir, famciclovir, valacyclovir - toxicity

Answer 11

1. obstructive cystalline neuropathy

2. acute renaL failure if not adequately hydrated

Question 12

Acyclovir, famciclovir, valacyclovir - resistance

Answer 12

Mutated viral thimidine kinase

Question 13

Ganciclovir - mechanism of action

Answer 13

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

Question 14

Ganciclovir - clinical use

Answer 14

CMV, especially in immunocomprommised patients

Question 15

Ganciclovir - oral

Answer 15

Valganciclovir, a prodrug of ganciclovir –> better oral bioavailability

Question 16

acyclovir and ganciclovir - oral

Answer 16

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

Question 17

ganciclovir - toxicity

Answer 17

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

Question 18

ganciclovir vs acyclovir according to toxicity on host cells

Answer 18

ganciclovir is more toxic to host enzymes than acyclovir

Question 19

ganciclovir - resistance

Answer 19

mutated viral kinase

Question 20

nucleic acid synthesis inhibitors - Guanosine analogs - drugs

Answer 20

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

Question 21

viral DNA polymerase inhibitors - drugs

Answer 21

1. Cidofovir

2. foscarnet

Question 22

Foscarnet - mechanism of action

Answer 22

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)

Question 23

Foscarnet inhibits

Answer 23

1. Viral DNA/RNA polymerase

2. HIV reverse transcriptase

Question 24

Foscarnet - clinical use

Answer 24

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

Question 25

Foscarnet - toxicity

Answer 25

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

Question 26

Foscarnet - mechanism of resistance

Answer 26

Mutated DNA polymerase

Question 27

viral DNA polymerase inhibitors - drugs

Answer 27

1. Cidofovir | 2. foscarnet

Question 28

Cidofovir - mechanism of action

Answer 28

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

Question 29

Cidofovir - clinical use

Answer 29

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

Question 30

cidofovir vs foscarnet according to half live

Answer 30

Cidofovir has LONG HALF LIVE

Question 31

Cidofovir - toxicity

Answer 31

nephrotoxicity

Question 32

Cidofovir - toxicity - solution

Answer 32

coadminister with probenecid and IV saline to decrease toxicity

Question 33

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

Answer 33

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

Question 34

antiviral - protein synthesis inhibitors - drugs

Answer 34

interderon-a

Question 35

interderon - α - mechanism of action as an antiviral

Answer 35

protein synthesis inhibitors

Question 36

Interferons as antivirals / types

Answer 36

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

Question 37

interferons - clinical use

Answer 37

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

Question 38

interferons - side effects

Answer 38

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

Question 39

antiviral therapy - uncoating agents - drugs - clinical use

Answer 39

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

Question 40

amantadine - clinical use and side effect

Answer 40

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