Pharmacology 1 Flashcards
what is a virus?
is an intracellular parasite that consists of DNA or RNA core surrounded by a protein coat and sometimes an outer covering of lipoprotein
How does a virus work?
the virus attaches itself to the host’s cell repleasing viral genetic material which takes control of the host cell machinery for replication. The host cell eventually dies releasing replicated viruses that proliferate and attack more and more host cells
are antivirals virustatic?
yes, they work bes when the host has a healthy immune system; so that when the rate of virus proliferation is slowed, the immune system releases appropriate cells to overcome virus’s attack and overcome the infection.
what are the factors that determine the effective treatment of viral infections?
host factors, virus factors and antiviral agent factors
what factors influence the outcome of antiviral therapy?
-stage of illness at the time of initation of therapy
-antiviral dose
-ability of the virus to penetrate the central nervous system
-ability of the virus to remain latent within its host
-development of antiviral resistance
Treatment of influenza?
Amantanes
neuraminidase inhibitors
What is the treatment for Amantanes?
treatment of influenza A
They are not effective against influenza B
MOA amantanes?
interfere with the uncoating of the influenza A virus, a necessary step in the viral replication process
what does neuraminidase inhibitors treat?
influenza A and B
The h1n1 and h3n3 strains of influenza A are susceptible to the effects of oseltamivir ad zanamivir.
MOA of neuraminidase inhibitors?
inhibit viral release and inhibit virus prolieration
Oseltamivir is formulated for? zanamivir if formulated for?
oral use
powder for oral inhalation
what drug is not recommended with pulmonary disease?
Zanamivir
Oseltamivir brand name?
Tamiflu
Zanamivir brand name?
Relenza
Treatment of hepatitis B and C?
Interferones
Nucleoside/neucleotide analogues
Direct acting antivirals
MOA of interferons?
they protect uninfected cells by promoting resistance to virus infection
inhibit viral transcription by activating enxymes that cleave single-stranded viral RNA
What is Nucleoside/Neucleotide analogue used for?
treatment of HBV
only Ribavirin is indicated for HBC (when combined with peginterferone alfa) and RSV
what is direct acting antivirals used for?
treatment of hepatitis C
most are marketed as combination products or taken in combination to improve effectiveness
what is the treatment of herpes simplex, herpes Zoster and cytomegalovirus?
Acyclocir, valacyclocir, foscarnet, ganciclovir, famciclovir, penciclovir, trifluridine
what does Acyclovir do?
inhibits viral DNA synthesis. it is used for the treatment of herpes simplex virus, herpes genitalis and varicella zoster virus.
Higher doses are reqiured for the treatment of chickenpox and shingles
what does valacyclocir do? moa
is an ester of acyclovir. it has greater oral absorption
it treats the same as acyclovir but reiuqres less frequent dosing
what does Foscarnet do? moa
Indicated for the treatment of CMV, HSV-1, HSV-2, herpes labialis (sold sores)
What does Ganciclovir do?
used in the treatment of CMV.
What 4 aux labels should be on Ganciclovir?
-swallow whole
-do not crush or chew
-avoid pregnacy
-take with food
what is famciclovir used for?
indicated for the treatment of HSV-1, HSV-2 and acute herpes zoster infections
has a longer duration of action than acyclovir
Acyclovir brand name?
Zovirax
Famciclovir brand name?
Famvir
Ganciclovir brand name?
Cytovene
Trifluridine brand name?
Viroptic
HIV attacks?
CD4 T lymphocytes and weakens the immune system
The steps of the HIV life cycle?
9 steps
-Binding
-Fusion
-Uncoating
-reverse transcription
-Integration
-Genome replication
-protein synthesis
-protein cleavage and viral assembly
-virus release
what are antiretrovirals?
medicines that interfere with the replication of retroviruses. HIV is a retrovirus
why are antiretrovirals are administered?
reduce viral load
increase CD4 counts
delay the development of AIDS-related conditions
imporve survival
Antiretrovirals 6 classes?
-Nucleoside/nucleotide reverse transcriptase inhibitors
-Non-nucleoside reverse transcriptase inhibitors
-protease inhibitors
-fusion inhibitors
-chemokine receptor antagonists
-hiv integrase strand inhibitor
therapy of antiretrovirals are based on what?
CD4 counts and patients are symptomatic or asymptomatic
what is HAART? AND WHY is it used?
Highly active antiretrovial therapy
used to reduce antiviral resistance and is a regimen of 3 or more medications from two or more antiretroviral classes is prescribed
what is done prior to antiretroviral?
agent resistance testing is recommended
Used in the catagory of Nucleoside and Nucleotide reverse transcriptase inhibitors?
Lamivudine, Zidovudine, Emtricitabine + Tenofovir, Efavirenz + Emtricitabine + Tenofovir
what is lamivudine used for?
effective aginst HIV and also inhibits replication of HBV. good choice of therapy for those who have HIV and HBV coninfections
what drug causes nail discoloration?
Zidovudine
Lamicudine brand name?
epivir
Zidovudine brand name?
Retrovir
what is Zidovudine?
first availble antiretroviral and is formulated for oral and parenteral administration
may be administered to pregnanct women and intravenously during delivery and as a suspesion
how does NNRTI’s and NRTIs differ?
-NNRTI’s are noncompetitive inhibitors of reverse transcriptase
-they do not need to be activated by host enxymes
-they are not effective against HIV-2