V 3 Antiviral Flashcards
what types of nucleic acid synthesis inhibitors are available in non-HIV families?
Guanine nucleotide synthesis inhibitor: Ribavirin
Viral DNA polymerase inhibitors: Foscarnet, Cidofovir
Guanosine analogs: Acyclovir, Ganciclovir
Oseltamivir mechanism and Clinical use
Inhibit influenza neuraminidase : release of progeny virus Treatment and prevention of both influenza A and B
zanamivir mechanism and Clinical use
Inhibit influenza neuraminidase : release of progeny virus Treatment and prevention of both influenza A and B
Acyclovir, famciclovir, valacyclovir mechanism
Guanosine analogs Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells: few adverse effects Triphosphate formed by cellular enzymes Preferentially inhibit viral DNA polymerase by chain termination
Acyclovir, famciclovir, valacyclovir toxicity
Obstructive crystalline nephropathy acute renal failure if not adequately hydrated
Acyclovir, famciclovir, valacyclovir mechanism of resistance
Mutated viral thymidine kinase
Acyclovir clinical use
HSV and VZV Weak activity against EBV No activity against CMV Used for HSVinduced mucocutaneous and genital lesions as well as for encephalitis Prophylaxis in immunocompromised patients No effect on latent forms of HSV and VZV
valacyclovir clinical use
a prodrug of acyclovir, has better oral bioavailability
famciclovir clinical use
For herpes zoster, use famciclovir
Ganciclovir mechanism
5′-monophosphate formed by a CMV viral kinase Guanosine analog Triphosphate formed by cellular kinases Preferentially inhibits viral DNA polymerase Preferentially inhibit viral DNA polymerase by chain termination
Ganciclovir clinical use
CMV, especially in immunocompromised patients Valganciclovir, a prodrug of ganciclovir, has better oral bioavailability
Ganciclovir toxicity
Leukopenia, neutropenia, thrombocytopenia, renal toxicity More toxic to host enzymes than acyclovir
Ganciclovir mechanism of resistance
Mutated viral kinase
