antivirals Flashcards
what two viruses is aciclivor used for
herpes simplex
varicella zoster virus
including: genital herpes, cold sores, shingles, chickenpox, encephalitis, etc.
what is herpes blepharitis
chronic form of herpes eye infection
what is valaciclovir
herpes pro drug
also CMV
how is CMV treated in immunocompromised patients
ganciclovir and valganciclovir
give examples of DNA viruses
HSV and HPV
What is positive sense RNA
similar to mRNA and can be immediately translated by the host cell
what enzyme is used to convert negative sense RNA to positive sense
RNA polymerase
what is retrovirus
creates a DNA copy of the viral RNA using reverse transcriptase which is found in the virus
some retroviruses can transform normal cells into cancer cells (Human T cell leukaemia virus)
what is a provirus
when the viral DNA has been incorporated into the genome of the host cell from a retrovirus
how do nucleoside reverse transcriptase inhibitors work
inhibit viral DNA synthesis by acting as a chain terminator
they look like thymidine so replace it but the chain is unable to continue after
how do non nucleoside reverse transcriptase inhibitors work
binding denatures the reverse transcriptase enzyme meaning the enzyme cannot produce viral DNA
name some NRTIs (nucleoside analogues)
zidovudine abacavir lamivudine didanosine zalcitabine stavudine
all have a 5’ trisphosphate group which can bind but do not offer the 3’ function which is required for attachment
require phosphorylation by viral/ cellular kinases
name some antiviral nucleoside analogues
used to treat HIV, herpes, RNA viruses
AZT (azidothymidine)
ganciclivor
ribavarin
acyclovir
how do protease inhibitors work
HIV codes for inert proteins which are then converted to functional proteins by proteases (virus specific)
protease inhibitors block these enzymes so the virus cannot produce functional proteins
name some protease inhibitors
atazanavir, indinavir, lopinavir, ritonavir, saquinavir
what are the 6 classes of antiretroviral drugs
nucleoside analogues (RTI) non nucleoside analogues (RTI) Protease inhibitors entry inhibitors fusion inhibitors integrase inhibitors
what are integrase inhibitors
Blocks the insertion of the viral DNA into the host DNA thereby stopping formation of the provirus
name an integrase inhibitor
raltegravir
elvitegravir
dolutegravir
what is a fusion inhibitor
blocks binding, fusion and entry of HIV into a cell
receptors: CD4, CCR5 or CXCR4
name some fusion inhibitors
maraviroc: CCR5 antagonist
enfuvirtide binds to gp41
what is HAART
Combination of 3-4 different drugs, usually 2x NRTIs + NNRTI, PI or integrase inhibitor
how do amantadine and rimantadine work (viral uncoating)
amatidine blocks a viral ion channel
rimantadine is concentrated in lysosomes and increases the ph of the compartment, which inteferes with the fusion of lysosomes and endocytosis of viral containing vesicles
Both block M2 ion channel functions
how do influenza inhibitors work
NA- neuraminidase blocker
cleaves sialic acid from the cell surface so that newly made viruses are released
NA inhibitors mimic sialic acid substrate by binding to the NA active site which halts viral replication
name some NA inhibitors
zanamivir (nasal spray)
tamiflu (tablet)
