Antiviral therapy Flashcards
Anti-HSV/VSV agents
Acyclovir (zovirax) Famciclovir (famvir) Valacyclovir (valtrex) These are all guanine nucleoside analogs. Inhibits viral DNA polymerase
Acyclovir (Zovirax)
80% renal excretion
Topical, oral, IV
Safe for pregnancy, lactation
When is acyclovir activated?
It is selectively activated in cells infected with herpes virus.
Uninfected cells do not activate acyclovir.
Acyclovir uses
Varicella, Zoster, Genital HSV
400-800mg PO QID
Acyclovir SE
Renal toxicity
Confusion, coma, somnolence
TTP/HUS
GI, HA, Rash, Anemia, photosensitivity
Famciclovir (Famvir)
Cyclic guanine analog
HSV1, 2. VZV, EBV
More bioavailability than zovirax
Famciclovir MOA
Converted to penciclovir in liver
Less affinity for DNA polymerase, but longer half life.
Famciclovir SE
Neutropenia, Thrombocytopenia
Neuro sx
GI, fatigue, HA, LFT’s
Valacyclovir (Valtrex)
Prodrug of acyclovir. Rapidly converted to acyclovir same MOA More pricey, more bioavailable Same SE as acyclovir
Which is the only antiviral to work for herpes encephalitis?
Acyclovir IV
What is the preferred drug for Zoster?
Acyclovir
Anti-CMV agents
Ganciclovir
Ganciclovir (Cytovene)
Oral, IV, intraocular
CMV, EBV, HSV/VZV, HHV-6
Preferred for CMV retinitis
Ganciclovir SE
Reversible pancytopenia
Renal dysfxn
psychiatric disturbances
Seizures
Influenza agents
Oseltamivir (Tamiflu)
Zanamivir
Amantadine
Rimantadine
Neuraminidase Inhibitors
Oseltamivir (Tamiflu)
Zanamavir
Prevent release of new virions from infected cell.
Used against A and B flu
Oseltamivir (Tamiflu)
Oral Neuraminidase Inhibitor
Flu A and B in kids and adults
Avian flu, H5N1
can cause N/V and HA
Zanamivir (Relenza)
Neuraminidase Inhibitor
Given via inhilation
Flu A, B, Avian flu
Amantadine (Symmetrel)
Rimantadine (Flumadine)
Prevent release of viral contents into host cell
Influenza A: frequent resistance
Not recommended in US for the flu…
Ribavirin
Purine nucleoside analog
Inhibits RNA polymerase
DNA and RNA viruses are affected
Ribavirin is drug of choice for?
RSV bronchitis and pneumonia in hospitalized children. Given as inhalation.
AND
Lassa Fever
Ribavirin is alternative drug for?
Influenza, parainfluenza, measles
Uses w/ interferons for HCV
Is ribavirin safe for pregnancy?
NO. Category X
Lactation probably unsafe as well
Ribavirin SE
BBW: Hemolytic anemia Resp. depression Suicide Bacterial infxns anxiety fatigue dizziness
Treatment for HBV and HCV?
Inteferons
