Viral Based Dzs

Question 1

What is famciclovir metabolized to?

Answer 1

penciclovir

Question 2

What are the 2 pro-drugs in this section?

Answer 2

valacyclovir and valganciclovir

Question 3

What is the MOA of acyclovir, famciclovir, ganciclovir, valacyclovir, and valganciclovir?

Answer 3

competitively inhibits viral DNA polymerase; competes w/ deoxyguanosine triphosphate for incorporation into viral DNA

Question 4

What is the MOA of cidofovir?

Answer 4

competitively inhibits viral DNA pol; competes w/ deoxycytosine triphosphate for incorporation into viral DNA

Question 5

What is the MOA of forscarnet?

Answer 5

selectively inhibits the viral specific DNA polymerases and reverses transcriptase at pyrophosphate-binding site; blocks chain elongation

Question 6

How is ganciclovir different from acyclovir?

Answer 6

it has a 3’OH group while acyclovir inserts monophosphate rather than 2’deoxyguanosine monophosphate into viral DNA

Question 7

How are cidofovir and forscarnet similar?

Answer 7

both don’t need IC kinase-dependent phosphorylation

Question 8

How are the anti-viral drugs eliminated?

Answer 8

renally so dose adjustment needed for renal disease. To minimize toxicity, pts need to take probenecid and hydration w/ normal saline

Question 9

What two drugs in this section don’t have cross-reactivity?

Answer 9

cidofovir and forscarnet

Question 10

adverse effect of acyclovir and valacyclovir?

Answer 10

neurotoxicity and seizures

Question 11

adverse effect of cidofovir?

Answer 11

nephrotoxicity - so monitor creatinine and urinary protein; probenecid HSR

Question 12

adverse effect of famciclovir?

Answer 12

NONE!!!

Question 13

adverse effect of forscarnet?

Answer 13

electrolyte imbalance - chelates Ca ions

Question 14

adverse effect of ganciclovir and valganciclovir?

Answer 14

anemia, leukopenia, neutropenia, pancytopenia, thrombocytopenia. Teratogen