Antivirals Flashcards
what do antivirals consist of
nucleic acid (DNA or RNA)
protein coat
sometimes lipid envelope
what specifically is a virus
an obligate intracellular parasite
what is an acute virus and give examples
rna viruses
influenza , measles, mumps, hep A
what are chronic viruses and give examples
DNA viruses
latent - herpes simplex and CMV
persistent - HIV, HTLV, Hep b and C
what are the 5 types of virus syndrome
rashes - non vesicular and vesicular respiratory infections gastroenteritis encephalitis/meningitis blood borne viruses
give examples of non-vesicular vs vesicular rashes in diseases
non = pink, raised, blotchy - measles rubella parvovirus adenovirus
vesicular - progress to fluid filled spot, chicken pox, herpes simplex, enterovirus
give two examples of respiratory infection gastroenteritis encephalitis/meningitis blood borne viruses
influenza A/B, Rhinovrius, COVID
Rotavirus, Norovirus
HSV, enterovirus, rabies
hepatitis, retrovirus
why aren’t all viruses treated
most are self-limiting
acute infections non treated
chronic infections are treated
immuncomprimised people are treated
what is used in the treatment of Herpes simplex Virus
aciclovir
what is used in the treatment of chickenpox and shingles (VZV)
aciclovir (only adults as children don’t need)
only can treat shingles if over 60 y/o
what is the treatment of influenza
neuraminidase inhibitors (oseltamivir - oral, zanamivir - inhaled) only treat high risk patients such as immunocomp, elderly, obese and children under 6 months
what is the problem with treating chronic viral infections
antiviral toxicity
challenge to maintain adherence - increased risk of resistance
which type of chronic viral infection can be cured
Hep C
how do viruses replicate
attach to cell receptor cell entry virus uncoats early proteins produced, viral enzymes replication late transcription/translation assembly release
what are the 4 mechanisms of target antivirals
DNA to DNA - DNA viruses (eukaryotes)
DNA to RNA - DNA viruses (eukaryotes)
RNA to RNA - RNA viruses (polymerase)
RNA to DNA - retroviruses (Hep B, reverse trascnrtipatse enzymes)
what is an example of a nucleoside reverse transcriptase inhibitor and what do they do
NRTI’s - inhibit reverse trasncriptase - AZT (azidothymidine) anti cancer drug but used to stop HIV replication - not used anymore due to mitochondrial toxicity
analogues inhibit reverse transcriptase - what is a pyrimidine / purine analogues
pyrimidine
thymidine analogue - zidovudine
cytosine - lamivudine
purine
A and G - abacavir and tenovovir
what is the treatment of Hep B
lamivudine (unless M184V mutation which resists this)
or tenofovir
give examples of herpesvirus polymerase inhibitors
aciclovir (chain terminator)
ganciclovir (brand spectrum - CMV, HHV6, HSV)
what is the treatment of hep C
RNA polymerase nucleotide inhibitors such as sofosbuvir
combination therapy 8-12 weeks
95% curable
give examples of non-nucleotide transcription inhibitors (NNRTI’s)
efavirenz
nevirapine
why are protease inhibitors used to treat viruses
viruses make poly proteins which are broken down by proteases to carry out viral actions so the protease is inhibited to stop this
what protease inhibitors are used for these diseases
HIV and Hep C
HIV - atazanavir, darunavir
Hep C - paritaprevir, grazoprevir
give two entry inhibitors of viruses
enfuviritide - fusion inhibitor
maraviroc - chemokine receptor antagonist
give two examples of integrate inhibitors
raltegravir, dolutegravir
what is HAART
highly active antiretroviral therapy
describe the HIV genome and competitive mutations
9000 nucleotides
every genome has at least one mutation
some mutations are advantageous such as M184V - resistance to lamivudine
