__________ is an inorganic pyrophosphate that inhibits all HSV and HIV.
Foscarnet is effective against _____ _____ CMV and _____ _____ HSV and VZV strains.
What is foscarnet's MOA?
It reversibly blocks the pyrophosphate binding site of viral polymerase non-competitively. This inhibits cleavage of pyrophosphate from dNTP's.
Resistance to foscarnet occurs through _____ _____ in the viral polymerase gene.
Foscarnet use can cause chronic __________. This leads to significant CNS disturbances like tremors and seizures.
Which of the following is not an indication for foscarnet?
A. Ganciclovir-resistant CMV retinitis
B. Acyclovir-resistant HSV infections
C. Zidovudine-resistant HIV
D. Prophylaxis for bone marrow transplants
__________ is an acyclic guanine nucleoside, similiar to acyclovir.
What is ganciclovir's prodrug form?
What infection is ganciclovir particularly effective against?
During HSV infection ganciclovir is initially phosphorylated by virally encoded _____ _____. A viral__________ phosphorylates it during CMV infection.
thymidine kinase, phosphotransferase
The di- and triphosphate forms of ganciclovir are phosphorylated by _____ _____.
The triphosphate form of ganciclovir is a competitive inhibitor for _____ at the viral DNA polymerase.
What happens when ganciclovir is incorporated into viral DNA?
It halts elongation.
How does viral resistance develop to ganciclovir?
Decreased phosphorylation due to mutations in the viral phosphotransferase gene and mutations in the viral DNA polymerase gene.
T/F Ganciclovir is more effective in acyclovir-resistant HSV.