antiviral medications Flashcards
what are 5 major categories antiviral medications are used for in clinical treatment
- Herpes
- cytomegalovirus
- influenza
- respiratory syncytial virus
- HIV
in the virus life cycle, where does the antiviral drug try to inhibit the process
- attachment/entry to host cell
- inhibit transcription/translation
- interference of viral assembly
what type of virus has a different order of life cycle
retrovirus
Ion channel blocker drugs Amantadine and Rimantadine require what type of envirnment
acidic environment
what consists of the herpesvises viruses
chichenpox
shingles
oral and genital herpes
hepadnaviruses is what type of virus
hep B
cytomegalosvirus is commenly seen in what type of patients
transplant patients
respiratory syncytial virus occurs is who and what it is
pneumonia and bronchiolitis in children
what is the mechanism of action for Acyclovir
- acyclovir is phosphorylated into monophostphate via thymidine kinase (HSV or VZV)
- monophosphate to triphosphate via cellular enzymes
in Acyclovir, what does the triphosphate form do?
acts as a chain terminator
what is the bioavailability of Acyclovir
low
Acyclovir can go where in the body pretty well
CSF
placenta
umbilical cord
what is an adverse effect of acylcovir if given with high dose bolus and IV formulation
Reversible nephrotoxicity do to crystalline nephropathy
what is a side effect for Acyclovir
headaches
hallucinations
seizures
what is the prodrug for acyclovir
valacylovir
what is the bioavailablity for Valacyclovir
excellent
when is valacylovir converted to acyclovir
first pass intestinal and hepatic metabolism
what is valacylovir and acyclovir used to treat
Genital Herpes simple
Genital Herpes zoster
what is the drug of choice for Encephalistis
IV acyclovir
what does Valacylovir treat
Genital Herpes simple
Genital Herpes zoster
what is the difference between Valacylovir and Acylcovir in dosing
valacylovir is less frequent dosing
what is the prodrug choice for Ganciclovir
Valganciclovir
what is the mechanism of action for Ganciclovir
similar acyclovir
What is the bioavailability for ganciclovir
low
for CMV ( cytomegalovirus) what is the best drug choice, why?
Ganciclovir
- less accumulated of phosphorylated acyclovir present in CMV then Ganciclovir
what is the adverse effects of Ganciclovir
headache
behavior changes
n/v
what does Ganciclovir treat
CMV retinitis
CMV prophylaxis in transplant patients
Valganciclovir has what MOA
similar to acyclovir/ganciclovir
what is the bioavailability for valganciclovir
good
what does valganciclovir treat
CMV Retinitis
CMV prophalaxis
what is the prodrug for penciclovir
famciclovir
what is the MOA for penciclovir
similiar to acyclovir
how is pencicvlovir available in the US
topical cream only
what is an adverse effect of penciclovir
application site of irritation
what is a clinical use for penciclovir
herpes simplex ( cold sores)
what is the bioavailbilty of famciclovir
good
how is famciclovir excreted
renal, requiring dose reductions
what is the clinical use for famciclovir
herpes simples
herpes zoster
what is the mechanism for docosanol
not similar to acyclovir MOA
Docosanol treats what
oral herpes simplex
Imiquimod treats
gential/perianal warts
podofilox treats
genital/ parianal warts
podophyllin treats
warts
Cidofovir has what MOA
different from acyclovir and ganciclovir
-interacts with DNA polymerase
what are adverse effects does Cidofovir have
nephrotoxicity
neutropnia
why is Cidofovir a second tier drug
high nephrotoxicity
When is Cidofovir used for
when ganciclovir fails to treat CMV retinitis
in order to reduce Cidofovir nephrotoxicity what do you do
- administer with normal Saline
- hydration
in order to treat CMV with Cidofovr, how must it be administered? when must it be taken
with probenecid
-before/after/maintenance dose
what is the mechanism of action for foscarnet
competes for pyrophosphate in viral DNA polymerase
what is the adverse effects of foscarnet
nephrotixicity n/v/d seizures anemia EKG changes severe electrolyte imbalances
in what tier is foscarnet used
second
what is the clinical use for foscarnet
- CMV retinits with AIDS patients
- when acyclovir is resistant to herpes simplex in immunocompromised patients
what does immune system in a bottle refer to
interferons
what are interferons
produced by body in response to virus infection
what is the gold standard in treatment for certain types of Hep B
interferon therapy
what are some symptoms for interferon therapy
sore, joint, pain
mock body’s natural reaction
when children receive interferon therapy what is a common adverse effect
personality changes
what is used after interferon therapy in order to improve pharmacokinetics
pegalated (polyethelene glycol)
what are the different types of interferons
Type I: alpha and beta
Type II: gamma
what is type I interferon alpha used for
hepB
condyloma acuminata
kaposi sarcoma
what is type I interferon beta used for
multiple sclerosis
what is Type II interferon gamma
- normally produced by T cells
- not commercially made
what is the mechanism of action for Lamivudine
inhibits reverse transcriptase
what is the bioavailability for Lamivudine
good
what is the adverse effect for Lamivudine
Black box warning: lactic acidosis and severe hepatomegaly
what does Lamivudine treat
- combo with interferons to treat hep B
- part of HIV treatment
Ribavirin MOA
unknown
which antiviral drug has good half life
Ribavirin
what are adverse effects of Ribavirin
combo with interferons increases anemia, fatigue, depression
what is Ribavirin used for
RSV bronchiolitis and pneumonia in hospitalized children
Imiquimod treats what
topical treatment for condylomata acuminate ( warts)
how well does Imiquimod treat warts
recurrence is common
Amantadine is similar to what other drug
Rimantadine
what is the mechanism of action for amantadine and rimantadine
prevents virus from entering host cell
what adjustment is required for amantadine but not for rimantadine
renal adjustment
Amantadine plays a role in what disease
5 tier drug for Parkinson’s
both Amantidine and Rimantadine are used clinically for what
treat and prevent influenza A
what are the adverse effects of amantidine and rimantadine
confusion, insomnia
more pronounced in amantidine
How is osteltamivir given
tablet
how is Zanamivir given, what does it cause
inhaler
cause wheezing/bronchospasm
what is the mechanism of action for osteltamivir and zanamivir
inhibits neuroaminidase which is required for the release of virus from infected cell
what is the clinical use for osteltamivir and zanamivir
influenza A and B
amantadine and rimantadine need what type of environment to work
low pH
what drugs are anti-herpetic
acyclovir, valacyclovir
penciclovir, famciclovir
what drugs are anti-CMV
cidofovir
foscarent
granciclovir
valganciclovir
what drugs are anti- influenza
amantadine
rimantadine
ostelmavir
zanamivir
what drugs treat hepatitis B/C
interferons +/- ribavirin, lamivudine
