Antivirals Flashcards
zanamivir mechanism
inhibits influenza neuraminidase –> prevents release of progeny virus
oseltamivir mechanism
inhibits influenza neuraminidase –> prevents release of progeny virus
clinical use zanamivir
influenza A and B
clinical use oseltamivir
influenza A and B
ribavirin mechanism
inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase
clinical use ribavirin
RSV, chronic hepatitis C
side effects ribavirin
- hemolytic anemia
2. severe teratogen
acyclovir, famciclovir, and valacyclovir mechanism
monophosphorylated by HSV/VZV thymidine kinase (not in uninfected cells –> few adverse effects)
guanosine analog
triphosphate formed by cellular enzymes
preferentially inhibits viral DNA polymerase by chain termination
clinical use acyclovir, famciclovir, and valacyclovir
HSV and VZV (weak activity against EBV)
no effect on latent forms
is acyclovir, famciclovir, valacyclovir useful for CMV?
NO!!
which -cyclovir has better oral bioavailability
valacyclovir
treatment of herpes zoster
famciclovir
side effects acyclovir, famciclovir, and valacyclovir
obstructive crystalline nephropathy and acute renal failure
how to prevent renal failure from acyclovir, famciclovir, and valacyclovir
hydration!
mechanism of resistance to acyclovir, famciclovir, and valacyclovir
mutated viral thymidine kinase
ganciclovir mechanism
5’-monophosphate formed by a CMV viral kinase
guanosine analog
triphosphate formed by cellular kinases
perferentially inhibits viral DNA polymerase
clinical use ganciclovir
CMV (esp. in immunocompromized)
what ganciclovir has better oral bioavailability
valganciclovir
treatment CMV retinitis
ganciclovir
side effects ganciclovir
- leukopenia
- neutropenia
- thrombocytopenia
- renal toxicity
mechanism of resistance to ganciclovir
mutated CMV DNA polymerase
lack of viral kinase
mechanism foscarnet
viral DNA polymerase inhibitor –> binds pyrophophate-binding site
does not require activation by viral kinase
clinical use foscarnet
CMV retinitis in immunocompromised pts when ganciclovir fails
acyclovir-resistant HSV
what to do when ganciclovir fails for CMV retinitis??
foscarnet!!
side effect foscarnet
nephrotoxicity
mechanism of resistance to foscarnet
mutated DNA polymerase
cidofovir mechanism
preferentially inhibits viral DNA polymerase
does not require phosphorylation by viral kinase
clinical use cidofovir
CMV retinitis in immunocompromised pts
acyclovir-resistant HSV
long half-life
side effects cidofovir
nephrotoxicity
how do you reduce the nephrotoxicity associated with cidofovir?
coadminister with probenecid and IV saline
what is atazanavir?
protease inhibitor
what is darunavir?
protease inhibitor
what is fosamprenavir?
protease inhibitor
what is indinavir?
protease inhibitor
what is lopinavir?
protease inhibitor
what is ritonavir?
protease inhibitor
what is saquinavir?
protease inhibitor
what is abacavir?
NRTI
what is didanosine?
NRTI
what is emtricitabine?
NRTI
what is lamivudine?
NRTI
what is stavudine?
NRTI
what is tonofovir?
NRTI
what is zidovudine?
NRTI
what is efavirenz?
NNRTI
what is nevirapine?
NNRTI
what is delaviridine?
NNRTI
what is raltegravir?
integrase inhibitor
what is enfuvirtide?
fusion inhibitor
what is maraviroc?
fusion inhibitor
protease inhibitor mechanism
prevent maturation of new viruses (asembly of virions depends on HIV-1 protease [pol gene], which cleaves polypeptide products into functional parts)
which protease inhibitor boosts other drug concentrations by inhibiting cytochrome P-450
ritonavir
side effects of protease inhibitors (3)
- hyperglycemia
- lipodystrophy (fat redistribution)
- nephropathy
which protease inhibitor causes hematuria?
indinavir
which HIV drugs cause fat redistribution?
protease inhibitors
which HIV drugs cause hyperglycemia?
protease inhibitors
mechanism NRTIs
competitively inhibit nucleotide binding to reverse transcriptase and terminate DNA chain (lack a 3’ OH group)