Exam 3: Antivirals

Question 1

What are the 3 antivirals for HSV/VZV?

Answer 1

Acyclovir, valacyclovir, and docosanol

Question 2

What are the 3 antivirals used for influenza?

Answer 2

Oseltamivir, zanamivir, and baloxavir

Question 3

What are the 3 antivirals used for Hepatitis B?

Answer 3

Tenofovir, entecavir, and lamivudine

Question 4

What are the 4 antivirals used for CMV/Herpes?

Answer 4

Ganciclovir, valganciclovir, Foscarnet, and Cidofovir

Question 5

What is the antiviral used for RSV?

Answer 5

Ribavirin

Question 6

What are the 2 antivirals used for Hep C?

Answer 6

Sofosbuvir/ledipasvir and Sofosbuvir/velpatasvir

Question 7

What is the DOC for HSV/VZV?

Answer 7

Acyclovir

Question 8

What is the MOA of acyclovir?

Answer 8

Phosphorylated/activated by viral thymidine kinase in infected cells
Inhibits DNA polymerase by competing with dGTP

Question 9

How does resistance to Acyclovir develop?

Answer 9

Decrease in thymidine kinase

Question 10

What are the adverse effects of acyclovir?

Answer 10

• Generally well tolerated because drug is mostly concentrated within virus.
• Nephrotoxicity with high IV doses (hydration is very important)
• Safe in pregnancy

Question 11

What is the MOA of Docosanol (abreva)?

Answer 11

Inhibits viral fusion to host plasma membrane so the virus cannot get into the cell

Question 12

What is docosanol used for?

Answer 12

OTC and topical for cold sores/herpes simplex.

Question 13

What is the MOA of Ganciclovir/valgancilovir?

Answer 13

Phosphorylated/activated by viral kinases in infected cells

Inhibits DNA polymerase

Question 14

What is the DOC for CMV?

Answer 14

Ganciclovir

Question 15

What are the toxicities associated with ganciclovir/valganciclovir?

Answer 15

• Myelosuppresion: Leukopenia, neutropenia, and thrombocytopenia
• CNS effects: headache, confusion, seizures

Question 16

What is the MOA of foscarnet?

Answer 16

Directly inhibits DNA and RNA polymerase and reverse transcriptase. Does not require phosphorylation for activity

Question 17

What kind of toxicity do all parental antivirals have? How should you combat this?

Answer 17

• They all are renal toxic

- Combated with aggressive hydration

Question 18

How is CMV encephalitis treated?

Answer 18

Foscarnet + ganciclovir

Question 19

How is CMV retinitis treated?

Answer 19

• Oral, IV, or ocular implant ganciclovir (replace ocular implant every 5-8 months)
• If ganciclovir resistant, treat with foscarnet

Question 20

What is the MOA of cidofovir?

Answer 20

• Inhibits viral DNA polymerase

- Does not require phosphorylation for activity

Question 21

Are are the toxicities associated with Cidofovir?

Answer 21

-Dose dependent nephrotoxicity

Question 22

What is the MOA of Oseltamivir/zanamivir?

Answer 22

Neuraminidase inhibitors, blocks the release of the virus from cells

Question 23

What are oseltamivir/zanamivir used to treat?

Answer 23

-Influenza A and B (start within 48 of symptom onset)

Question 24

Who are oseltamivir and zanamivir approved for?

Answer 24

• Oseltamavir: oral, approved for patients >1 year

- Zanamavir: Nasal or oral inhaler, approved for patients > 7 years

Question 25

What is the MOA of Baloxavir Marboxil (XoFluza)?

Answer 25

-Endonuclease activity of the PA protein, the drug prevents viral gene transcription and ultimately viral replication

Question 26

What is the use of Baloxavir Marboxil?

Answer 26

- Active against influenza A and B if started within 48 hours - Approved for > 12 years, single dose

Question 27

What is the MOA of Ribavirin?

Answer 27

- Inhibits RNA polymerase and synthesis of GTP | - Phosphorylated by host enzymes

Question 28

What is Ribavirin used for? | How can it be administed?

Answer 28

- RSV (aerosol) and hepatitis C | - Aerosol, IV, Oral

Question 29

What are the toxicities associated with ribavirin?

Answer 29

- Oral: Dose dependent hemolytic anemia - Aerosol: Respiratory depression, cardiac arrest, hypertension - IV: Psychiatric, depression, suicide Extremely teratogenic, do no conceive for at least 6 months after exposure to drug

Question 30

What is the DOC for hepatitis B?

Answer 30

Tenofovir

Question 31

What is the MOA for Tenofovir?

Answer 31

Inhibits HBV DNA polymerase; reverse transcriptase inhibitor also used for HIV

Question 32

What is the MOA of Entevcavir?

Answer 32

Inhibits HBV DNA polymerase

Question 33

What is the MOA of Lamivudine?

Answer 33

Inhibits HBV polymerase

Question 34

What two hepatitis B drugs have a good safety profile, even in those with advanced disease?

Answer 34

Tenofovir and entecavir

Question 35

What is the MOA of sofosbuvir?

Answer 35

Inhibits viral NS5B RNA polymerase, blocking replication of HCV when the uridine analogue is incorporated, causing termination

Question 36

What is the MOA of Ledipasvir/Velpatasvir?

Answer 36

Inhibits HCV NS5A protein and may prevent phosphorylation and replication