Shared Flashcard Set

Details

Antiviral Drugs
What doesn't kill you makes you stronger :) I didn't go very detailed on this, so if you want more read the syllabus
28
Pharmacology
Graduate
08/29/2010

Additional Pharmacology Flashcards

 


 

Cards

Term
MOA and clinical effects of rimantidine and amantidine
Definition
both block the uncoating on the viral RNA inside the human cells by interfering with the function of the viral M2 protein which functions as an ion channel
redcue symptoms if tx begun within 48h of onsect, prophylaxis decreases risk of infection by 50-90%
Resistance has rendered these drugs in effective for most current flu viruses
Rimantadine has fewer CNS S/E so better for elderly and renal disease
decrease duration of symptoms for 1 day
Term
MOA and therapeutics of Zanamavir and Oseltamivir
Definition
Zan nasal spray and oseltamivir oral, both expensive
both block the release of new viral particles from infected cells via the inhibition of viral neuraminidase
Term
DOC for HSV1 and HSV2
Definition
valacyclovir
F = 48%
valis the prodrug which is converted to acyclovir
oral tx with valacyclovir results in plasma acyclovir concentrations that are 3-5x greater than those achieved with oral acyclovir
decrease dose with renal failure
Term
Acyclovir bioavail
Definition
poor, so use valacyclovir
Term
MOA of acyclovir, valacyclovir, penciclovir, ganciclovir, and valganciclovir
Definition
inhibit viral DNA synthesis so they are not effective agaisnt non-replicating, latent viruses
the triphosphate forms of acyclovir and ganciclovir compete with dGTP at the viral DNA polymerase and also causes chain termination when incorporated into the viral DNA
Term
most common form of Res to acyclovir
Definition
mutation of the viral thymidine kinase which prevents the conversion of acyclovir to acyclovir monophosphate
Term
MOA and therapeutic use of cidofovir
Definition
cidofovir is an analog of cytosine nucleotide which is converted to the active diphosphate by host-cell enzymes
the active diphosphate inhibits the viral DNA polymerase and is incorporated into the viral DNA
Used to treat CMV retinities
Term
Drugs used to treat CMV retinitis
Definition
ganciclovir - DOC
valganciclovir
cidofovir
foscarnet
fomivirsen
Term
MOA of Foscarnet
Definition
given IV, it is an inorganic pyrophosphate which acts directly to inhibit viral DNA and RNA polymerases and HIV erverse trnscriptase
no activation via viral or host cell enzymes is required
used to treat HSV and VZV which are resistant to acyclovir
used to treat CMV which is resistant to ganciclovir and cidofovir
Term
MOA and therapeutic use of trifluridine, aka trifluorothymidine
Definition
Trifluridine is converted to trifluridine triphosphate by host-cell enzymes: the active metabolite inhibitis viral DNA synthesis
Ocular drops are used to treat herpes keratitis, by HSV
Term
MOA and therapeutic use of vidarabine
Definition
host cell enzymes produce the active metabolite vidarabine triphosphate which inhibits viral DNA polymerase
ocular drops are used to treat herpes keratitis
Term
MOA and therapeutic use of docosanol
Definition
inhibits the fusion of the lipid enveloped herpes virus with the plasma membrane of the cell. Since the virus is not able to enter the cell viral replication is blocked
Used to treat oral -facial herpes keratitis
Term
Therapeutic uses of po acyclovir and valacyclovir
Definition
DOC for HSV
fever blisters - begin therapy
primary or recurrent genital herpes
suppressive therapy for recurrent genital herpes
treatment of HSV proctitis
herpes zoster - dermatomes shingles
Resist is low
S/E of acyclovir and val = N/V, diarrhea and headache
Term
HSV thymidine kinase
Definition
converst active drug to monophosphate form which cannot be done by the host cell by itself
from there the host cell continues phosphorylation to create a nucleoside analog that interupts replication
Term
Fusion inhibitors
Definition
enfuvirtide
a synthetic peptide which blocks fusion fo the viral and T-cell membrans so HIV cannot enver the CD4 T cell
Enfuvirtide shows no cross res with other classes of antiretroviral drugs
Used to treat patients who exhibit high viral loads despite continued therapy
Term
NRTI MOA
Definition
nucleoside reversoe transcriptase inhibitors
these nucleosides are converted to "false" nucleotides (triphos) by intracellular kinases, they competitively inhibit HIV reverse transcriptase and cause chain termination of the viral DNA
Term
The NRTI's
Definition
zidovudine
lamivudine
stavudine
didanosine
zalcitabine
abacavir
emtricitabine
tenofovir
abacavir + lamivudine + zidovudine
Term
HIV post exposure prophylaxis
Definition
zidovudine + lamivudine
Term
Often effective when HIV has become Res to NRTIS'
Definition
tenofovir
Term
NNRTI MOA
Definition
non-nucleoside reverse transcritpate inhibitors
do not require phosphorylation to be active inhibitors
directly inhibit reverse transcriptase to stop HIV replication
bind to a site different than that of NRTI's and thus do not compete with nucleotides for binding to the reverse transcriptase
net effect is the blockade of both reverse transcriptase and DNA-dep DNA polymerase
Term
NNRTI drugs
Definition
neviraphine
delavirdine
efavirenz
Term
NNRTI Resistance
Definition
Resistance develops quickly with monotherapy b/c all of these drugs have the same MOA
Resistance to one NNRTI means resistance to all NNRTI's
Used with NRTI's b/c they have a different MOA
Many Cyp450 reactions
Term
NRTI Resistance
Definition
some cross resistance in this class b/c each of the drugs has a slightly different MOA
Term
Integrase inhibitors
Definition
raltegravir given p.o.
MOA: blockade of viral integrase prevents the insertion of viral DNA into human DNA
used to treat MDR HIV infections
Term
Protease inhibitors MOA
Definition
Block viral protease to prevent the cleavage of viral polyproteins into the final stuctural proteins needed for the assembly of the mature virion core required for infectious particles
Term
PI drugs:
Definition
saquinavir
ritonavir
indinavir
nelfinavir
amprenavir
atazanavir
lopinavir+ritonavir
Term
Ritonavir drug interaction
Definition
ritoavir is an inhibitor of CYP2A4 thus giving increased concentrations of lopinavir since this CYP metabolizes saquinavir
thus ritonavir is a pharmacokinetic enhancer
Term
Treatment of RSV
Definition
palivizumab is a monoclonal antibody directed against a surface proteins of RSV
used for prophylactic therapy in high-risk infants
i.m. once monthly
Supporting users have an ad free experience!