Antivirals

Question 1

Acyclovir

Answer 1

guanosine analog

1st phosphorylated by viral thymidine kinase

inhibits DNA polymerase

Use:
HSV1, HSV2, VZV, EBV (HHV1-4)
start as early as possible

Question 2

Valcyclovir

Answer 2

Valyl ester of acyclovir

hydrolyzed to acyclovir

Question 3

Famciclovir

Answer 3

prodrug of penciclovir

acyclic guanosine nucleoside analog
relies on viral thymidine kinase

HSV1, HSV2, VZV (HHV1-3)

Question 4

Gancyclovir

Answer 4

activated by CMV viral kinase

inhibits viral DNA polymerase

AE: bone marrow suppression
“Gang’s up on BM”
renal toxicity

Question 5

Foscarnet

Answer 5

inhibit DNA polymerase

does NOT require activation by viral kinase

AE: renal toxicity
anemia

Use: resistant HSV
CMV retinitis in immunocompromised

Question 6

Neuraminidase inhibitors

Answer 6

Zanamivir
Oseltamivir

block release of virions from host cell

for severe influenza or high risk - elderly, chronic dz

start w/in 24-48 hours of sx

Question 7

Ribavirin

Answer 7

guanosine analog

Use: RSV (limited benefit), HepC -chronic

SE: teratogenicity
Hemolytic anemia