Antiviral Therapy Flashcards
1
Q
Zanamivir, oseltamivir
mechanism
clinical use
A
- inhibit influenza neuraminidase
- decreases release of progeny virus
- treatment & prevention of influenza A & B
2
Q
Ribavirin
mechanism
A
- inhibits synthesis of guanine nucleotides
- competitively inhibits inosine monophosphate dehydrogenase
3
Q
Ribavirin
clinical use
toxicity
A
- RSV, chronic HepC
- Hemolytic anemia, severe teratogen
4
Q
Acyclovir, famciclovir, valacyclovir
mechanism
A
- 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
Q
Acyclovir, famciclovir, valacyclovir
clinical use
A
- 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
Q
Acyclovir, famciclovir, valacyclovir
toxicity
A
- obstructive crystalline nephropathy
- acute renal failure if not adequately hydrated
7
Q
Acyclovir, famciclovir, valacyclovir
resistance
A
mutated viral thymidine kinase
8
Q
Ganciclovir
mechanism
A
- 5’-monophosphate formed by CMV viral kinase
- guanosine analog
- triphosphate formed by cellular kinases
- **inhibits viral DNA pol **
9
Q
Ganciclovir
clinical use
A
- CMV (immunocompromised)
- valganciclovir
- prodrug
- better oral bioavailability
10
Q
Ganciclovir
toxicity
A
- leukopenia
- neutropenia
- thombocytopenia
- renal toxicity
11
Q
Ganciclovir
resistance
A
- mutated CMV DNA pol
- lack of viral kinase
12
Q
Foscarnet
mechanism
A
- **viral DNA pol inhibitor **
- binds pyrophosphate-binding site of enzyme
- doesn’t require activation by viral kinase
13
Q
Foscarnet
clinical use
A
- CMV retinitis (immunocompromised) when ganciclovir fails
- acyclovir-resistant HSV
14
Q
Foscarnet
toxicity
resistance
A
- nephrotoxicity
- mutated DNA pol
15
Q
Cidofovir
mechanism
A
- preferentially **inhibits viral DNA pol **
- doesn’t require phosphorylation by viral kinase