Antivirals

Question 1

what are the antivirals for influenza

Answer 1

neuraminidase inhibitors: Oseltamivir and Zanamivir

M2 inhibitors: Amantadine and Rimantadine

Question 2

in depth mechanism of neuraminidase inhibitors (name them)

Answer 2

Oseltamivir and Zanamivir

neuraminidase cleaves sialic acid residues from viral and surface proteins of infected cells –> promotes virion release and prevents clumping of newly released virions

the above drugs inhibits this process

Question 3

which strain of flu do the neuraminidase treat (name them)

Answer 3

Oseltamivir and Zanamivir

Influenza A and B

Question 4

most common adverse effects of Oseltamivir

Answer 4

nausea, vomiting, diarrhea, abdominal pain, insomnia, vertigo, and neuropsychiatric issues

Question 5

adverse effects of Zanamivir

Answer 5

it’s inhaled so usually well tolerated

acute bronchospasm in those with breathing difficulties (asthma and COPD)

Question 6

mechanism of M2 inhibitors (name them)

Answer 6

Amantadine and Rimantadine

inhibits replication of influenza virus by inhibiting M2

Question 7

what strain of influenza do the M2 inhibitors work on (name them)

Answer 7

Amantadine and Rimantadine

Influenza A because it is the only one that has the M2 protein

Question 8

adverse effects of M2 inhibitors (name them)

Answer 8

Amantadine and Rimantadine

anxiety, disorientation, headache

neuro effects are less severe and more frequent with rimantadine

Question 9

which set of anti flu medication would you give to pregnant women

Answer 9

neuraminidase inhibitors

Oseltamivir and Zanamivir

Question 10

what are the antivirals for hepatitis

Answer 10

Interferon
Ribavirin
Nucleoside/Nucleotide Analogues: Entecavir and Lamivudine
Protease Inhibitors: Boceprevir and Telaprevir

Question 11

what is the selective antiviral action of IFNalpha due to

Answer 11

activation of host cell ribonuclease that preferentially degrades mRNA

Question 12

adverse effects of interferons

Answer 12

flu like symptoms, neurological problems, and depression in those with pre-existing mood disorders

Question 13

what is ribavirin’s antiviral activity reversed by

Answer 13

guanosine

Question 14

mechanism of ribavirin

Answer 14

inhibitor of influenza RNA polymerase and mRNA guanylyltransferase

Question 15

two drugs used together for treatment of HCV

Answer 15

Ribavirin and IFNalpha

Question 16

adverse effects of ribavirin

Answer 16

sudden deterioration of resp function
cardiovascular effects
hemolytic anemia
SEVERE depression, suicidal ideation, relapse of drug abuse

Question 17

contraindication of ribavirin

Answer 17

Pregnant women and their male partners

Pre-existing Psychiatric Disorders

Question 18

what are the protease inhibitors used for treatment in hepatitis

Answer 18

Boceprevir and Telaprevir

Question 19

mechanism of boceprevir

Answer 19

binds reversibly to HCV nonstructural 3 protein thereby inhibiting viral replication

Question 20

adverse effect of boceprevir

Answer 20

flu like illness
anemia – fatigue
nausea
dysgeusia – distortion of sense of taste

Question 21

mechanism of telaprevir

Answer 21

same as boceprevir - binds reversibly to HCV nonstructural 3 protein thereby inhibiting viral replication

Question 22

adverse effects of telaprevir

Answer 22

anemia, leucopenia, neutropenia, rash

Stevens Johnson rash

Question 23

mechanism of the nucleos(t)ide analogues used for treatment of hepatitis (name them)

Answer 23

Lamivudine and Entecavir

competitive inhibition of HBV DNA polymerase

also have anti HIV properties

Question 24

mechanism of Lamivudine

Answer 24

cytosine analogue that is phosphorylated to its active 5 triphosphate metabolite before incorporation into viral DNA by HBV polymerase then causes chain termination

Question 25

mechanism of Entecavir

Answer 25

guanosine analogue inhibits three functions of HBV DNA polymerase: - priming of the HBV DNA polymerase - reverse transcription of the negative strand from the pregenomic RNA - synthesis of positive strand HBV

Question 26

antiviral drugs for Herpes

Answer 26

``` Acyclovir Ganciclovir Penciclovir Cidofivir Foscarnet Trifluridine ```

Question 27

what is acyclovir used to treat

Answer 27

guanosine analogue used to treat HSV and VZV

Question 28

mechanism of acyclovir

Answer 28

turned into acyclovir triphosphate by viral thymidine kinase and human enzymes --> competitive substrate for viral DNA polymerase --> incorporated into DNA chain --> terminate DNA replication

Question 29

how is acyclovir's bioavailability increased

Answer 29

use of valacyclovir, valyl ester formulation of acyclovir

Question 30

big adverse effect of acyclovir

Answer 30

nephrotoxicity

Question 31

what is ganciclovir used to treat

Answer 31

acyclic 2'-deoxyguanosine analogue used in the treatment of CMV herpes

Question 32

mechanism of ganciclovir

Answer 32

it is triphosphorylated with first phosphate addition by viral UL97-encoded kinase and other two by human cellular enzymes then incorporated onto DNA chain --> termination of DNA replication

Question 33

what is ganciclovir used to treat

Answer 33

CMV retinitis in AIDs patient Herpes simplex keratitis CMV prophylaxis in transplant patient

Question 34

most common side effect of ganciclovir

Answer 34

reversible bone marrow suppression

Question 35

mechanism of penciclovir

Answer 35

guanine analogue that gets triphosphorylated then inhibits DNA polymerase activity since it is a competitive inhibitor for deoxyguanosine triphosphate

Question 36

what does penciclovir treat

Answer 36

HSV-1, HSV-2, and VZV

Question 37

major clinical indication for cidofovir

Answer 37

CMV retinitis especially those resistant against ganciclovir

Question 38

mechanism of foscarnet

Answer 38

non nucleoside pyrophosphate analogue that inhibits pyrophosphate binding to DNA polymerase hence suppressing HSV-1, HSV-2, and CMV replication

Question 39

most common adverse effect of all these antiviral herpes drug

Answer 39

nephrotoxicity

Question 40

special adverse effect of foscarnet

Answer 40

other than nephrotoxicity, electrolyte imbalance

Question 41

mechanism of Trifluridine

Answer 41

thymidine analogue that inhibits thymidylate synthetase and incorporates into viral DNA in place of thymidine

Question 42

use of trifluridine

Answer 42

opthalmic ointment so used for keratoconjunctivitis and recurrent epithelial keratitis caused by herpes

Question 43

adverse effect of trifluridine

Answer 43

transient irritation of eye | palpebral edema