Antivirals Flashcards
Three types of host defense against virus
Specific barriersNonspecific cellular barrierimmune system
Vaccine based on person exposure to ____ in order to make ______
chemically deactivated virusesAntibodies
Antiviral drugs generally inhibit ______ or _______
ReplicationAttachment
Nonspecific defenses (1st and 2nd lines)
1st = skin, mucous membrane2nd = WBC, antimicrobial proteins, inflammation
Third line of host defense is based on _____ and consists of _____ and ______
ImmunityLymphocytes and AB’s
Three types of vaccines
InactivatedAttenuatedEngineered
Inactivated vaccine has destroyed _____, and intact ______
genomecapsid
____ is an inactivated vaccine
Polio
Attenuated vaccine replicates ______. Examples are _____ and _____
SlowlyChickenpox, MMR
Engineered vaccines have ____ that are produced by ________
viral proteinsyeast cells
Example of genetically engineered vaccine
Hep B
Why do we need antivirals? (6 reasons)
–No vaccine or problems with them–Mutation–Reassortment–New infections–TIME to make vaccines–Immunosuppressive diseases
Antivirals – barriers to making effective ones? (6)
Selective toxicityResistanceIntracellular bugsDelay of SymptomsLatent phase hard to targetLimited drug development
Successful drug intereferes with either…
Viral functionCell function that virus needs
There are antivirals against which viruses?
HSV, VZV, CMVHIVInfluenza A + BHep B + C
Six targets for antivirals (steps)
Before attachmentAttachmentPenetration/uncoatingReplication of genomeProtein synthesisAssembly/release
Viral disruption is effective against ______ viruses
enveloped
Nonoxynol (N9) is a ______ againse ___ and ____
DetergentHSV, HIV
Citric acid disrupts…
rhinovirus
The first group of viral attachment blocking agents rely on _____. This interferes with ____ and causes ______
neutralizing antibodiesInterferes with Binding to receptorsCauses aggregation of viral particles
Maraviroc is a _______. What is its mechanism
CCR antagonistChanges CCR5 shape so it cant bind gp120
Viral attachment blockers have three groups, which are…
Neutralizing antibodiesReceptor antagonistsFusion inhibitors
Fusion inhibitor example and general mechanism.
enfuvirtidestop HIV entry to CD4 cells
Enfuvirtide mimics…
HR2 region of gp41(gp41 is fusion protein for HIV)
Uncoating blocker example
Adamantanes–amantadine–rimantadine
Amantadine is a _______ that targets ______. This disrupts _______
Weak organic baseM2 proteinDisrupts H2 Transport, which inhibits uncoating of viral genome.
Amantadine is effective against….
Influenza ANOT B
Amantadine may cause ______ due to _______
HallucinationDopaminergic action
Nucleic Acid Synthesis blocked by ___ and ____
Nucleoside anaolgsNon-Nucleoside analogues
Nucleoside analogs inhibit _____.
VIral polymeraseCauses chain termination
Nucleoside analogs that target viral Polymerase: examples (4 groups)
Acyclovir, gancyclovirAZTCidofovir/TenofovirTelbivudine
Nucleoside analogs can also cause ______. Examples? (3)
errors in replication and transcriptionRibavirinTFTIdoxuridine
Non nucleoside analog examples
FoscarnetNevirapine
Nucleoside analog mechanism
conveted by VIRAL (1) then CELLULAR (2) enzymes to TRIPHOSPHATE form
Triphohsphate form of Nucl. Analogs inhibit _____. Then they are…
DNA and RNA pol.Incorporated into DNA
The Nucl. Analogs have a ____ group that has been substituted for the usual ___ group
N3 (azide) group instead of OH
Valacyclovir is…
soluble, has better availability
Penciclovir form:
cream
Famciclovir form:
Oral
Acyclovir Tx for
HSV 1 and 2
Acyclovir can be thought of as a ______
purine mimic
Acyclovir inhibits ______
Viral DNApol 100X AFFINITY
Acyclovir activated by
Thymidine kinasesViralHostHost
Acyclovir has ____ oral absorption rate
15-30%
Gancyclovir is a synthetic analog of _______
2’-deoxy-guanosine
Gancyclovir used for
CMV— retinitisPneumoniaColitis