Antivirals

Question 1

What are the three mechanisms of antivirals?

Answer 1

Inhibition of viral genome replication

Inhibit viral uncoating

Inhibition of viral release

Question 2

What is the mechanism of acyclovir?

Answer 2

Phosphorylated via HZV or VZV thymidine kinase

Question 3

What is the distribution of acyclovir?

Answer 3

Good CSF penetration for treatment of viral meningitis

Question 4

How is acyclovir eliminated?

Answer 4

Renally

Requires dose reduction

Question 5

What are the adverse effects of acyclovir?

Answer 5

Reversible nephrotoxicity

Crystalline nephropathy with high dose

CNS - HA, Hallucinations and Seizures

Question 6

What is the mechanism of Valacyclovir?

Answer 6

PO, essentially completely converted to acyclovir

Question 7

What are the symptoms and treatment of HSV encephalitis?

Answer 7

Fever, Focal neurologic symptoms

Treatment - IV acyclovir

Question 8

What topical antiviral is used to treat oral herpes simplex?

Answer 8

Dcosanol (Abreva)

Question 9

What topical antivirals are used to treat genital/perianal warts?

Answer 9

Imiquimod

Podofilox

Question 10

What is podophyllin used for?

Answer 10

25% liquid administered in clinic directly to wart

Question 11

What is used to treat CMV Retinitis?

Answer 11

Ganciclovir

Question 12

What is the MOA of Ganciclovir?

Answer 12

Similar to acyclovir, but 10x more potent than acyclovir against CMV

Question 13

What are the adverse effects of Ganciclovir?

Answer 13

CNS w/ Behavior changes and headache

N/V

Neutropenia and Thrombocytopenia

Question 14

What is Valaganciclovir used to treat?

Answer 14

CMV retinitis

CMV prophylaxis

Question 15

What is used to to treat HSV cold sores?

Answer 15

Penciclovir as topical cream

Question 16

What is used to treat HSV and HZ?

Answer 16

Famciclovir

Question 17

What is the mechanism of Penciclovir and Famciclovir?

Answer 17

Similar to that of acyclovir

Question 18

What is the use of Cidofovir?

Answer 18

Reserved for CMV retinitis when other treatments fail

Administer with normal saline to decrease chances of nephrotoxicity

Question 19

What is the MoA of Foscarnet (Foscavir)?

Answer 19

Competes for pyrophosphate in viral DNA polymerases

Question 20

What are the ADRs of foscavir?

Answer 20

Nephrotoxic

Seizures, Anemia, Neutropenia

EKG changes - 1st degree AV Block

Hyper/Hypotension

Question 21

What are the clinical uses for Foscavir?

Answer 21

Second line agent

CMV in AIDS patients

Acyclovir resistant Herpes Simplex in immunoscompromised ptns

Question 22

What is the MoA of Amantadine and rimantadine?

Answer 22

Prevents virus from entering host cell

Question 23

What does amantadine require that rimantadine does not?

Answer 23

Amantadine requires renal adjustment

Rimantadine does not

Question 24

What are the ADRs for amantadine and rimantadine?

Answer 24

Confusion, Insomnia

More pronounced with amantadine

Question 25

What is the clinical use of amantadine and rimantadine?

Answer 25

Treat and prevent Influenza A

Amantadine has a small roll in Parkinsons

Question 26

What is the MoA of Osteltamivir and Zanamivir?

Answer 26

Inhibits neuroaminidase which is required for the release of the virus from infected cells

Question 27

What are the ADRs of Osteltamivir?

Answer 27

PO causes GI side effects

Question 28

What are the ADRs of Zanamivir?

Answer 28

Dry powder may cause wheezing and bronchospasm

Avoid COPD/Asthma patients

Question 29

What are the clinical uses of osteltamivir and zanamivir?

Answer 29

Both Px and Tx Influenza types A and B