Viral diseases Flashcards
Tx of infections; MOA; elimination; dose mod for dysfxn; assoc. neurologic, teratogenic or immune suppressive actions
What is acyclovir indicated to treat?
varicella zoster; varicella chicken pox
What is cidofovir indicated to treat?
pox virus; HHV-6; HHV-7;
What is drug is metabolized to the active product, penciclovir?
famciclovir
What is famciclovir used to treat?
varicella zoster
What is forscarnet indicated to treat?
HHV-6
Indication for ganciclovir?
HHV-6; HHV-8;
Which are viral prodrugs?
valacyclovir; valganciclovir
Indications for valacyclovir?
varicella zoster; varicella chicken pox;
indications for valganciclovir?
HHV-6; HHV-8
How does acyclovir prevent further viral chain elongation?
insertion of acyclovir monophos into viral DNA so viral polymerase cannot remove the acyclovir moiety
Why is ganciclovir not block further viral DNA synthesis?
it has a 3’ OH group
What is the MOA of foscarnet?
pyrophosphate binding site of viral DNA polymerase and prevents cleavage of pyrophosphate to stall primer template extension
Which drugs have the MOA of competitively inhibits viral DNA polymerase; competes with deoxyguanosine-TP for incorporation into viral DNA?
acyclovir; famciclovir; ganciclovir; valacyclovir; valganciclovir
How does the MOA of cidofovir differ from the other “virs”?
competes with deoxyCYTOSINE-TP for viral DNA incorpation
What is significant when considering dose adjustment in the antivirals?
renal elimination so dose adjustment necessary in renal dysfxn => if not renal failure may occur
What is a toxicity of acyclovir and valacyclovir?
neurotoxicity including seizures
What is the toxicity of cidofovir?
Nephrotoxicity and probenecid hypersensitivity
What is important to monitor during the administration of cidofovir?
to prevent nephrotoxicity monitoring creatinine and urinary protein is necessary
What antiviral is not associated with toxicity?
famciclovir
What is the toxicity of forscarnet?
electrolyte imbalance => chelates Ca ions
What are the toxicities of ganciclovir and valganciclovir?
anemia; leukopenia; neutropenia; pancytopenia; thrombocytopenia; teratogen
How is renal toxicity minimized in patients receiveing cidofovir?
oral probenecid and hydration with normal saline concurrently to effectively reduce concentration and lower magnitude of clearance
The dose-limiting adverse reaction of intravenous cidofovir is what?
dose-dependent renal tubular necrosis (proximal tubule cell injury) beginning as soon as the first one or two doses
