Drugs Four Last Time Flashcards
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Herpesvirus group and ones there is treatment for
- Herpes simplex
- Varicella zoster
- cytomegalovirus
- epstein barr (no treatment)
Acyclovir
Agent of choice for herpes symplex and varicella zoster virus functions to inhibit viral DNA poly and incorporate into strand of viral DNA blocking further growth through cell conversion into acyclo-GMP
Acyclovir absorption
Topical, oral, IV
Acyclovir ADR’s
None!
Acyclovir resistance (3)
- decreased production of thymidine kinase
- alteration of thymidine kinase
- alteration of viral DNA poly so its less sensitive to inhibition
Acyclinovir is not a…
…cure for the virus, it just decreases symptoms
Vlacyclovir
More popular prodrug form of acyclovir, approved for PO therapy in immunocompetent host
Vlacyclovir ADR
Immunocompromised patients experience thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS)
Famciclovir
-Same as acyclovir but used only for acute herpes zoster and herpes simplex genitalis
Penciclovir
Topical drug indicated for recurrent herpes labialis (cold sores) in immunocompetent adults caused by HSV1 and 2
Docosanol
OTC treatment for herpes labialis, inhibits fusion btwn plasma membrane and viral envelope increasing healing with first sign of coldsore
Ganciclovir
Synthetic antiviral agent with activity against cytomegaolvirus
CMV in immunocompromised patient (AIDS) leads to…
CMV retinitis and eventual blindness
Valganciclovir
Prodrug version of ganciclovir with PO formulation but same indications for CMV retinitis and prevention and results
Ganciclovir ADRs
serious ADRS such as granulocytopenia and thrombocytopenia and hsould be restricted to treat CMV in immunocompromised host
Cidofir
Alternate for ganciclovir requiring fewer IV infusions
Cidofir ADRs
- Nephrotoxicity
- Probenecid and IV hydration therapy with each dose
- granulocytopenia
Foscarnet
Alternative for ganciclovir for CMV retinitis, IV antiviral but does not cause granulocytopenia or thrombocytopenia
6 diff hepatitis viruses and do they become chronic
A B chronic (most common) C chronic (most common) D chronic E G
Hep C genotypes and their resistance
Genotype 1 - resistant, 75%
2-6 - susceptible, 25%
Direct acting antivriral drugs (DAAs)
Target specific steps in HCV replication without damage to healthy cells, often used in combination to decrease viral resistance
Categories of DAAs
1) NS3/4A protease inhibitors
2) NS5A inhibitors
3) NS5B nucleoside polymerase inhibitors (NPIs)
4) NS5B non nucleoside polymerase inhibitors (NNPIs)
Triple therapy regimen
Original standard of care for HepC until DAA development, includes pegylated interferon alfa (notorious for causing damage to host cell), protease inhibitor, and ribavirin
Interferon alfa
prevents viral entry into cells, synthesis of viral RNA and proteins, and viral release
Interferon alfa ADRs
- Flu like symptoms
- Mental health
- alopecia
Ribavirin
Combining with interferon alfa significantly improves responsiveness
Ribavirin ADRs
Hemolytic anemia and birth defects
2nd wave protease inhibitors used in triple therapy regimen
- grazoprevir
- paritaprevir
- simeprevir
- glecapavir
- voxilaprevir
Protease inhibitor mech of action (simeprevir)
Inhibits protease specific to HCV genotype 1 or 4 stopping replication, used in combo with other anti HCV drugs
NS5A inhibtors
Target nonstructural proteins necessary for HCV RNA replication, resistance can develop easily so agents should never be given alone
Example of an NS5A inhibitor
Daclatasvir
NS5B inhibitors
Target proteins necessary for HCV RNA replication,
NS5B NPI vs NNPI
NPI low likelihood of viral resistance, NNPI high likelihood
Ganciclovir Mech of action
Conversion to active form within host cell gangciclovir triphosphate, competes for binding to viral DNA poly and incorporates into DNA chain causing termination
Interferon alfa absoroption
-paraenterally usually subqutaneous
Daclatasvir
PO acting antiviral drug approved for use for treatment of crhonic hep C or HCV virus
Daclatasvir ADRs
Severe bradycardia when administered with other drugs
Sofosbuvir
NS5B NPI metabolized by liver into active form acts on RNA poly, well tolerated
Ledipasvir and sofosbuvir (harvoni)
Two PO antiviral agents used as a popular combination to treat HCV today
Viekira pak
Fixed dose of two direct acting antiviral agents obmitasvir and paritaprevir (similar efficacy to harvoni but higher pill burdern and greater potential for drug reactions)
Elbasvir/grazoprevir (zepatier)
Combo of NS5A inhibitor and NS3/4A protease inhibitor
Technivie
Direct acting antiviral drugs combine ombinasvir and paritaprevir for treatment of chronic hep C
Sofosbuvir/velpatasvir/voxilaprevir (Vosevi)
Fixed combo of nucleotide poly inhibitor, NS5A inhibitor nd NS3/4A protease inhibitor
Unlike Hep C, for Hep B we have a…
..vaccine
7 drugs used for chronic hep B
1) alfa interferon
2) peginterferon alfa
3) lamivudine
4) adefovir
5) entecavir
6) telbivudine
7) tenofovir
Influenza exists as these 2 types and what causes most infections, as well as what are the 2 types of surface antigens
A - 95% of infections
B - 5%
Hemmagglutinin and neurominidase (H#N#)
3 types of influenza vaccine
1) Inactivated
2)recombinant hemaglutinin vaccine
3) live attenuated vaccine
No more flu mist :(
Guillain barre syndrome and its relationship to the flu vaccine
Severe paralytic illness, 1976 flu vaccine associated with GBS, but no link ever since
Precautions to flu vaccine
- acute febrile illness should absolve before vaccination
- chicken egg protein residual
Who should receive the flu vaccine?
All people age 6 months or older unless severe allergic anaphylactic rxn
Fluzone
High dose with 4x amount of antigen recomended for older adults
Amantadine and Rimantidine
Antiviral drugs for prophylaxis and treatment of infections caused by type A influenza, mostly resistance strains now so not recommended
Neuraminidase Inhibitors
Modestly suppress influenza A AND B, prophylacitc and treatment
Olsetamivir
PO drug for treatment of uncomplicated influenza for those who have symptoms for no more than 2 days
Olsetamivir mech of action
Inhibits neuraminidase viral enzyme required to for replication
Zanamivir ADRs
Bronchospasm is greatest concern
Zanamivir absorption
Oral inhalation