What drugs are available to treat the Pox virus family?
What drugs are available to treat Varicella zoster?
-valacyclovir and acyclovir
-famciclovir (metabolized to active product, penciclovir)
What drugs are available to treat Varicella chicken pox?
What drugs are available to treat HHV-6?
-valganciclovir and ganciclovir
What drugs are available to treat HHV-7?
What drugs are available to treat HHV-8?
-famciclovir (metabolized to active product, penciclovir)- for recurrent herpes labialis
How do DNA viruses replicate?
2) Uncoating and transfer of viral DNA to hsot nucleus
3) protein synthesis
4) budding and release
How do acyclovir, famciclovir, and ganciclovir work?
competively inhibit viral DNA polymerase; competes with dexoygunaoisine triphosphate for incorporation into viral DNA
How does foscarnet work?
selectively inhibits viral-specific DNA polymerases and reverse transcriptases at pyrophosphate-binding sites to block chain elongation
How does cidofovir work?
competitively inhibits viral DNA polymerase by competing with deoxycytosine triphosphate for incorporation into viral DNA
Note about antivirals
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
How are these antivirals eliminated?
Renal, dose adjustment needed
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?
-acyclovir and valacyclovir
-ganciclovir and valganciclovir
AEs of acyclovir?
neurotoxic and seizures
AEs of cidofovir?
nephrotoxic (patients should receive probenecid and hydration with normal saline concurrently)
AEs of famciclovir?
AEs of ganciclovir?
pancytopenia and teratogenic