HNNS L12 - Anti-Viral Drugs

Question 1

Maraviroc

Answer 1

Inhibit viral attachment
(CCR5 on T cells)
*HIV

Question 2

Sialidase

Answer 2

Inhibit viral attachment

*Influenza, parainfluenza

Question 3

Enfuvirtide

Answer 3

Inhibit fusion of virus

*HIV

Question 4

Amantadine

Answer 4

Inhibit viral membrane protein M2
- Disrupt hydrogen transport from the acidic vacuole into the virion

*Influenza A, NOT B

Question 5

Ramantadine

Answer 5

Inhibit viral membrane protein M2
- Disrupt hydrogen transport from the acidic vacuole into the virion

*Influenza A, NOT B

Question 6

Ribavirin

Answer 6

Phosphorylated by adenosine kinase to ribavirin-TP

• Inhibit viral RNA polymerase
• HCV, RSV

Question 7

Favipiravir

Answer 7

Viral RNA polymerase inhibitor

Question 8

Interferon alpha

Answer 8

Block viral RNA transcription, protein synthesis and augment immune response

Chronic hepatitis B
- With lamivudine
Hepatitis C
- With ribavirin and new protease inhibitors (boceprevir, telaprevir)

Question 9

Peginterferon-alpha2a/b

Answer 9

Conjugated with polyethylene glycol

Prolong persistence of drug in blood

Question 10

Acyclovir

Answer 10

Nucleoside analogue
- Phosphorylated to ACV monophosphate by viral thymidine kinase
- Further phosphorylated to ACV-TP by cell enzymes
ACV-TP
- Selective (competitive) inhibition of viral DNA polymerase
- Chain termination by incorporation into viral DNA
*HSV, VZV

Question 11

Valaciclovir

Answer 11

Valine ester of acyclovir

• Pro-drug with better oral bioavailability (much higher serum level - reduce frequency of dosage)
• Broken down to acyclovir and valine spontaneously in blood

Question 12

Ganciclovir

Answer 12

Phosphorylated by CMV enzyme UL97

• Myelosuppression
• Poor oral bioavailability
• Cover HSV, VZV already

Question 13

Valganciclovir

Answer 13

Valine ester of ganciclovir

- Rapidly converted to ganciclovir in intestinal epithelial cells

Question 14

Famciclovir

Answer 14

Nucleoside analogue

• competitive inhibition of viral DNA polymerase
• Chain termination of viral DNA

Question 15

Zidovudine

Answer 15

NRTI (nucleoside / nucleotide reverse transcriptase inhibitor)

• Phosphorylated by cell enzyme to ZDV-TP
• Selective (competitive) inhibition of viral polymerase reverse transcriptase
• DNA chain terminator
• Some non-specific inhibition of cell polymerase

Question 16

Lamivudine

Answer 16

NRTI

• competitive inhibition of viral reverse transcriptase
• DNA chain terminator

*Some non-specific inhibition of cell polymerase

Question 17

Abacavir

Answer 17

NRTI

Question 18

Nevirapine

Answer 18

NNRTI

Question 19

Efavirenz

Answer 19

NNRTI

Question 20

Raltegravir

Answer 20

Integrase inhibitor

Question 21

Saquinavir

Answer 21

HIV Protease inhibitors

Question 22

Indinavir

Answer 22

HIV Protease inhibitors

Question 23

Ritonavir

Answer 23

HIV Protease inhibitors

Question 24

Nelfinavir

Answer 24

HIV Protease inhibitors

Question 25

Boceprevir

Answer 25

HCV protease inhibitor

Question 26

Telaprevir

Answer 26

HCV protease inhibitor

Question 27

Oseltamivir

Answer 27

Neuraminidase inhibitor

Question 28

Zanamivir

Answer 28

Neuraminidase inhibitor

Question 29

Cidofovir

Answer 29

Nucleotide analogue

• inhibit viral DNA polymerase
• chain termination

*For Drug resistance to acyclovir

CMV, HSV, VZV
No cross-resistance with acyclovir or ganciclovir

Compared with acyclovir / ganciclovir:

• More renal toxicity
• Less myelotoxicity

Question 30

Foscarnet

Answer 30

Directly blocks viral DNA polymersase

CMV, HSV, VZV
No cross-resistance with acyclovir or ganciclovir

Compared with acyclovir / ganciclovir:

• More renal toxicity
• Less myelotoxicity