Antiviral Therapy Flashcards Preview

First Aid: Microbiology > Antiviral Therapy > Flashcards

Flashcards in Antiviral Therapy Deck (16):
1

Zanamivir, oseltamivir 

mechanism

clinical use 

  • inhibit influenza neuraminidase 
  • decreases release of progeny virus 
  • treatment & prevention of influenza A & B 

2

Ribavirin

mechanism 

  • inhibits synthesis of guanine nucleotides 
  • competitively inhibits inosine monophosphate dehydrogenase 

3

Ribavirin

clinical use 

toxicity 

  • RSV, chronic HepC
  • Hemolytic anemia, severe teratogen 

4

Acyclovir, famciclovir, valacyclovir 

mechanism 

  • monophosphorylated by HSV/VZV thymidine kinase & not phosphorylated in uninfected cells
  • few adverse effects 
  • guanosine analog 
  • triphosphate formed by cellular enzymes 
  • preferentially inhibits viral DNA polymerase by chain termination 

5

Acyclovir, famciclovir, valacyclovir

clinical use 

 

  • HSV, VZV
  • weak activity against EBV
  • no activity against CMV
  • HSV-induced mucocutaneous & genital lesions
  • encephalitis 
  • prophylaxis in immunocompromised patients 
  • valacyclovir 
    • prodrug of acyclovir
    • better oral bioavailability 
  • famciclovir - herpes zoster 

6

Acyclovir, famciclovir, valacyclovir 

toxicity 

  • obstructive crystalline nephropathy
  • acute renal failure if not adequately hydrated

7

Acyclovir, famciclovir, valacyclovir 

resistance 

mutated viral thymidine kinase

8

Ganciclovir 

mechanism 

  • 5'-monophosphate formed by CMV viral kinase
  • guanosine analog 
  • triphosphate formed by cellular kinases
  • inhibits viral DNA pol 

9

Ganciclovir 

clinical use 

  • CMV (immunocompromised)
  • valganciclovir 
    • prodrug
    • better oral bioavailability 

10

Ganciclovir 

toxicity 

  • leukopenia
  • neutropenia
  • thombocytopenia
  • renal toxicity 

11

Ganciclovir 

resistance 

  • mutated CMV DNA pol 
  • lack of viral kinase 

12

Foscarnet 

mechanism 

  • viral DNA pol inhibitor 
  • binds pyrophosphate-binding site of enzyme 
  • doesn't require activation by viral kinase 

13

Foscarnet 

clinical use 

  • CMV retinitis (immunocompromised) when ganciclovir fails 
  • acyclovir-resistant HSV

14

Foscarnet

toxicity 

resistance 

  • nephrotoxicity 
  • mutated DNA pol

15

Cidofovir 

mechanism 

  • preferentially inhibits viral DNA pol 
  • doesn't require phosphorylation by viral kinase

16

Cidofovir 

clinical use 

toxicity 

  • CMV retinitis (immunocompromised)
  • acyclovir-resistant HSV
  • long t1/2