Antivirals Flashcards
Viruses depend on what to live?
host cell machinery
Antiviral drugs are only active against what type viruses?
only replicating viruses, not latent viruses
What are 6 sites antiviral drugs work at?
- viral attachment and entry
- uncoating
- nucleic acid synthesis
- transcription/translation
- packaging/assembly
- release
What drugs block viral attachment and entry?
Enfuvirtide
Docosanol
Maraviroc
Palivizumab
What drugs block penetration?
interferon-alfa
What drugs block uncoating?
amantadine and rimantadine
What drugs block nucleic acid synthesis?
NRTIS, NNRTIs, nucleoside/nucleotide analogs
What drugs block integration/transcription?
INSTIs
What drug block viral protein synthesis?
PIs
What drugs block viral release from host cell?
neurominidase inhibitors
How is influenza classified?
antigenic differences
Antigenic variation in influenza occur as?
drift and shifts
Drifts are
epidemics, minor changes like point mutations
Shifts are
pandemics, major genetic changes resulting in alterations of antigen structure usually caused by reassortment
Anti-influenza drugs may work at sites of?
packaging/assembly and release
Neurominidase inhibitors are active against?
Both influenza A and B
What are 3 neurominidase inhibitors?
Oseltamivir
Zanamivir
Peramivir
Oseltamivir
Tamiflu
Zanamivir
Relenza Diskhaler
Peramivir
Rapivab
Oseltamivir formulation and half life
oral, 6-10 hrs
Oseltamivir excretion
kidney
Oseltamivir dose adjustment
renal dysfunction
Oseltamivir adverse effects
GI upset, headache
Zanamivir formulation
inhaler
Zanamivir adverse effects
potential bronchospasms so not recommended for pts with asthma/COPD
Peramivir formulation
single IV dose
Peramivir adverse effects
diarrhea, skin hypersensitivity
All neurominidase inhibitors all have the potential to cause?
neuropsychiatric events like confusion delirium, and hallucinations
What drug blocks influenza endonuclease and prevents cap snatching?
Baloxavir Marboxil
Baloxavir Marboxil
Xofluza
Baloxavir Marboxil approved when and formulation
2018, single oral dose
Baloxavir Marboxil metabolism
UGT1A3 (glucuronidation) and CYP3A4
Baloxavir Marboxil half life and excretion
79.1 hrs and primarily in feces
Baloxavir Marboxil adverse effects and counseling
2 degree bacterial infections and avoid taking with dairy products
Large, double stranded DNA genome, icosahedral capsid and envelope
Herpes viruses
HSV1 is typically associated with?
orolabial ulcers
HSV1 drug treatments
Docosanol OTC, Peniciclovir
Docosanol
Abreva
Docosanol (Abreva) moa
prevents viral entry
Penciclovir
Denavir
Penciclovir moa
triphosphate form competes with dGTP for viral polymerase, inhibits replication
HSV2 is associated with
anogenital ulcers
Commonly known as chickenpox, can later emerge as herpes zoster
Varicella zoster virus
Infects severely immunocompromised/HIV pts, infection often the result of viral reactivation
cytomegalovirus
Guanosine analog that is monophosphorylated by viral TK
acyclovir
Oral nucleoside analog for treatment of HSV2
acyclovir
Acyclovir moa
nucleoside analogs prevent viral replication
Acyclovir
Zovirax
Acyclovir formulation and absorption
topical and IV, poorly absorbed but small doses can improve absorption
Acyclovir half life and excretion
2.5 hrs, excreted in urine
Acyclovir SE and monitoring
GI upset, neurotoxicity, and renal impairment
monitor urinalysis, BUN, SCr, LFTs, CBC
Prodrug of acyclovir used for treatment of HSV2
valacyclovir
Valacyclovir
Valtrex
Valacyclovir metabolism and absorption
converted by 1st pass intestinal or hepatic metabolism and rapid GI absorptions
Valacyclovir formulation, half life and excetion
oral, 2.5 hr, and excreted in urine
Valacyclovir ADE and drug interactions
thrombotic thrombocytopenic purpura/hemolytic uremic syndrome and interacts with cimetidine or probenecid