Antivirals

Question 1

Zanamivir/Olseltamivir MOA & Coverage

Answer 1

inh. influenza neuraminidase –> decreases viral relase form cells

Covers Influenza A and B

Question 2

Ribaviron MOA

Answer 2

Inh. synth of guanine nucleotides–competitively inh. IMP dehydrogenase

Question 3

Ribaviron coverage

Answer 3

RSV

Chronic HCV

Question 4

Ribaviron toxicity

Answer 4

SEVERE TERATOGEN–no prego around while being administered by inhalation

hemolytic anemia

Question 5

Acyclovir MOA

Answer 5

Inh. DNA polymerase by chain termination

guanosine analog

Question 6

Why is acyclovir so specific?

Answer 6

monophosphorylated by HSV/VZV thymidine kinase

only active in infected cells

Question 7

Axyclovir coverage

Answer 7

HSV
VZV
EBV (weak)

Infxns. must be active. does not work on latent

NO ACTIVITY AGAINST CMV

Question 8

What has better bioavailability than acyclovir and why?

Answer 8

Valacyclovir–prodrug

Question 9

Famciclovir use

Answer 9

Herpes Zoster

Question 10

resistance to acyclovir

Answer 10

mutated viral thymidine kinase

Question 11

Gancyclovir MOA

Answer 11

preferentially inh. viral DNA polymerase

Guanosine analogue

Question 12

How is gancyclovir activated?

Answer 12

5’-monophosphate formed by CMV viral kinase

Question 13

Gancyclovir coverage

Answer 13

CMV

Especially IC pts.

Question 14

what is the gancyclovir prodrug with better bioavailability

Answer 14

gancicyclovir

Question 15

Gancyclovir tox

Answer 15

pancytopenia
renal toxicity

more toxic to host than acyclovir

Question 16

Gancyclovir resistance

Answer 16

no DNA polymerase

no viral kinase (not activated)

Question 17

Foscarnet MOA

Answer 17

Inh. viral DNA polymerase that binds to pyrophosphate binding site of enzyme

Question 18

Does foscarnet require activation?

Answer 18

NO

Question 19

Foscarnet use

Answer 19

CMV retinitis in IC pts. when gancyclovir fails

Acyclovir resistant HSV

Question 20

Foscarnet toxicity

Answer 20

nephrotoxicity

Question 21

foscarnet resistance

Answer 21

mutated DNA polymerase

Question 22

Cidofovir MOA

Answer 22

preferentially inh. viral DNA pol

does not need to be activated

Question 23

Cidofovir use

Answer 23

CMV retinitis in IC pts. when gancyclovir fails

Acyclovir resistant HSV

Question 24

Cidofavir toxicity? How is it prevented?

Answer 24

nephrotoxicity

Give probenecid and IV saline to reduce

Question 25

2 Rx used when gancyclovir or acyclovir have failed

Answer 25

foscarnet
cidofavir (long T 1/2)

Question 26

Protease Inh. MOA

Answer 26

prevents HIV-1 protease (pol gene) from breaking into polypeptide product to make mRNA

no maturation of new viruses

Question 27

PI toxicity

Answer 27

hyperglycemia
GI
Lipodystorphy
Hematuria
Nephropathy

Question 28

NRTI MOA

Answer 28

Competetive inh. of nucleotide binding to reverse transcriptase –> terminates DNA chain

Question 29

NNRTI and NRTI toxicity

Answer 29

bone marrow suppression
peripheral neuropathy
lactic acidosis
rash
anemia

Question 30

Bone marrow suppression reversal with NNRTI/NRTI

Answer 30

EPO and G-CSF

Question 31

Rx used to reduce vertical transmission during pregnancy

Answer 31

Zidovudine (ZDV)–NRTI

Question 32

NNRTI’s

Answer 32

Nevirapine
Efavirenz
Delavirdine

Question 33

Raltegravir MOA

Answer 33

Inhibits HIV genome integration into host cell chromosome

reversibly inh. HIV Integrase

Question 34

Raltegravir tox

Answer 34

hypercholesterolemia

Question 35

HBV/HCV Tx (IFN)

Answer 35

IFN-alpha

ß for MS
(Y for NADPH oxidase def–CGD)

Question 36

How do IFN inhibit viruses?

Answer 36

block replication of RNA and DNA

Gp secreted by infected cells

Question 37

IFN toxicity

Answer 37

Neutropenia

myopathy