Viral Derm Treatment

Question 1

What drugs are available to treat the Pox virus family?

Answer 1

Cidofovir

Question 2

What drugs are available to treat Varicella zoster?

Answer 2

• valacyclovir and acyclovir
• famciclovir (metabolized to active product, penciclovir)

Question 3

What drugs are available to treat Varicella chicken pox?

Answer 3

• valacyclovir
• acyclovir

Question 4

What drugs are available to treat HHV-6?

Answer 4

• cidofovir
• foscarnet
• valganciclovir and ganciclovir

Question 5

What drugs are available to treat HHV-7?

Answer 5

Cidofovir

Question 6

What drugs are available to treat HHV-8?

Answer 6

• cidofovir
• famciclovir (metabolized to active product, penciclovir)- for recurrent herpes labialis
• ganciclovir
• valacyclovir only

Question 7

How do DNA viruses replicate?

Answer 7

1) attachment
2) Uncoating and transfer of viral DNA to hsot nucleus
3) protein synthesis
4) budding and release

Question 8

How do acyclovir, famciclovir, and ganciclovir work?

Answer 8

competively inhibit viral DNA polymerase; competes with dexoygunaoisine triphosphate for incorporation into viral DNA

Question 9

How does foscarnet work?

Answer 9

selectively inhibits viral-specific DNA polymerases and reverse transcriptases at pyrophosphate-binding sites to block chain elongation

Question 10

How does cidofovir work?

Answer 10

competitively inhibits viral DNA polymerase by competing with deoxycytosine triphosphate for incorporation into viral DNA

Question 11

Note about antivirals

Answer 11

Some drugs require sequential phosphorylation to the triphosphate form (active product). Thus, kinase deficient viral strains are inherently resistant to these agents. By contrast, cidofovir and foscarnet retain activity in such conditions because they act in a different manner

Question 12

How are these antivirals eliminated?

Answer 12

Renal, dose adjustment needed

Question 13

Another thing to note about antivirals, is that, similar to penicillins and select cephalosporins, there is the issue of cross-reactivity in some of these drugs with hypersensitivity due to similar structure (and thus should not be looked to as alternatives following reaction to one). What are these?

Answer 13

• acyclovir and valacyclovir
• famciclovir
• ganciclovir and valganciclovir

Question 14

AEs of acyclovir?

Answer 14

neurotoxic and seizures

Question 15

AEs of cidofovir?

Answer 15

nephrotoxic (patients should receive probenecid and hydration with normal saline concurrently)

Question 16

AEs of famciclovir?

Answer 16

None

Question 17

AEs of ganciclovir?

Answer 17

pancytopenia and teratogenic