Antiviral therapy

Question 1

Anti-HSV/VSV agents

Answer 1

Acyclovir (zovirax)
Famciclovir (famvir)
Valacyclovir (valtrex)
These are all guanine nucleoside analogs.
Inhibits viral DNA polymerase

Question 2

Acyclovir (Zovirax)

Answer 2

80% renal excretion
Topical, oral, IV
Safe for pregnancy, lactation

Question 3

When is acyclovir activated?

Answer 3

It is selectively activated in cells infected with herpes virus.
Uninfected cells do not activate acyclovir.

Question 4

Acyclovir uses

Answer 4

Varicella, Zoster, Genital HSV

400-800mg PO QID

Question 5

Acyclovir SE

Answer 5

Renal toxicity
Confusion, coma, somnolence
TTP/HUS
GI, HA, Rash, Anemia, photosensitivity

Question 6

Famciclovir (Famvir)

Answer 6

Cyclic guanine analog
HSV1, 2. VZV, EBV
More bioavailability than zovirax

Question 7

Famciclovir MOA

Answer 7

Converted to penciclovir in liver

Less affinity for DNA polymerase, but longer half life.

Question 8

Famciclovir SE

Answer 8

Neutropenia, Thrombocytopenia
Neuro sx
GI, fatigue, HA, LFT’s

Question 9

Valacyclovir (Valtrex)

Answer 9

Prodrug of acyclovir.
Rapidly converted to acyclovir
same MOA
More pricey, more bioavailable
Same SE as acyclovir

Question 10

Which is the only antiviral to work for herpes encephalitis?

Answer 10

Acyclovir IV

Question 11

What is the preferred drug for Zoster?

Answer 11

Acyclovir

Question 12

Anti-CMV agents

Answer 12

Ganciclovir

Question 13

Ganciclovir (Cytovene)

Answer 13

Oral, IV, intraocular
CMV, EBV, HSV/VZV, HHV-6
Preferred for CMV retinitis

Question 14

Ganciclovir SE

Answer 14

Reversible pancytopenia
Renal dysfxn
psychiatric disturbances
Seizures

Question 15

Influenza agents

Answer 15

Oseltamivir (Tamiflu)
Zanamivir
Amantadine
Rimantadine

Question 16

Neuraminidase Inhibitors

Answer 16

Oseltamivir (Tamiflu)
Zanamavir
Prevent release of new virions from infected cell.
Used against A and B flu

Question 17

Oseltamivir (Tamiflu)

Answer 17

Oral Neuraminidase Inhibitor
Flu A and B in kids and adults
Avian flu, H5N1
can cause N/V and HA

Question 18

Zanamivir (Relenza)

Answer 18

Neuraminidase Inhibitor
Given via inhilation
Flu A, B, Avian flu

Question 19

Amantadine (Symmetrel)

Rimantadine (Flumadine)

Answer 19

Prevent release of viral contents into host cell
Influenza A: frequent resistance
Not recommended in US for the flu…

Question 20

Ribavirin

Answer 20

Purine nucleoside analog
Inhibits RNA polymerase
DNA and RNA viruses are affected

Question 21

Ribavirin is drug of choice for?

Answer 21

RSV bronchitis and pneumonia in hospitalized children. Given as inhalation.
AND
Lassa Fever

Question 22

Ribavirin is alternative drug for?

Answer 22

Influenza, parainfluenza, measles

Uses w/ interferons for HCV

Question 23

Is ribavirin safe for pregnancy?

Answer 23

NO. Category X

Lactation probably unsafe as well

Question 24

Ribavirin SE

Answer 24

BBW: Hemolytic anemia
Resp. depression
Suicide
Bacterial infxns
anxiety
fatigue
dizziness

Question 25

Treatment for HBV and HCV?

Answer 25

Inteferons