C.5.Agents to treat HSV, VZV, CMV, RSV infection. Anti-influenza agents. Flashcards
mechanism of action of Acyclovir, Valacyclovir, and Famciclovir
thymidine kinase monophosphorylates the agents–> they are bioactivated by host-cell kinases to the triphosphate form
triphosphate form inhibits viral DNA polymerase
how is Acyclovir given?
topical, oral, IV
how can we reduce Cidofovir’s toxic renal effects?
co-administration with probenecid
which agent has the highest bioavailability- acyclovir or Valaciclovir?
valaciclovir–> 70%
acyclovir–> 15%
what is the 1st line agent for CMV?
Ganciclovir
treatment and prophylaxis
list the antiviral agents used for VZV
acyclovir
valaciclovir
famciclovir
ganciclovir
when do we give IV acyclovir
HSV encephalitis and neonatal infection
when do we use acyclovir?
HSV-1, HSV-2, VZV
prophylaxis for immunocompromised
which agent has the longest T1/2- Acyclovir or valaciclovir?
valaciclovir
acyclovir is short
when is valaciclovir &famciclovir used?
VZV (including shingles)
what is the function of antiherpetic agents?
antimetabolites
except Foscarnet!!
what are the indications for giving Ganciclovir
- CNV 1st line
- prophylaxis in solid organ and bone marrow transplantation
- HSV-1, HSV-2, VZV
what type of elimination do we have in Ganciclovir and Foscarnet?
renal
directly proportional to creatinine clearance
what are the side effects of Ganciclovir
bone marrow suppression mucosits, gastroenteritis hepatic dysfunction seizures (in overdose) crystalluria (nephrotoxic)
in which agent is it important to maintain hydration?
Cidofovir
what does Cidofovir do?
it’s activated by host cell kinase and become diphosphate–> which inhibits viral DNA polymerase
what is the resistance mechanism of Cidofovir and Foscarnet?
changes in DNA polymerase gene
what is the mechanism of Foscarnet
inhibits viral RNA and DNA polymerase