Antibiotics VI (Antivirals) Flashcards
What are the agents used to treat DNA viruses and their respective viruses?
- Nucleoside analogs for HSV/VSV (acyclovir)
- Nucleoside analogs for CMV (ganciclovir)
- Pyrophosphate analog for HSV/VSV/CMV (Foscarnet)
What are the generalizable MOA of the antivirals for DNA viruses?
- Typically prodrug
- Require bioactivation
- Active cogener binds to the nucleic acid polymerase
- Cogener lacks essential functional group to continue replication
- Termination of nucleic acid synthesis
What is a vital characteristic that applies to all antivirals?
The must have a greater affinity for viral activating enzyme than the mammalian counterpart
What is acyclovir active against?
HSV and VZV
What is ganciclovir effective against?
CMV in HIV patients
Which disease requires a higher dose of acyclovir? HSV or VZV?
VZV
Why is acyclovir so widely used? What are its SEs?
Relatively well-tolerated
CNS side effects (seizures, altered mental status) can occur if IV acyclovir is dosed inappropriately
What is the structure that ganciclovir mimics?
guanine analogue specifically for CMV
What is the main utility of ganciclovir?
Tx and prophylaxis of CMV retinitis in HIV
SEs of ganciclovir?
- Neutropenia and Thrombocytopenia are major dose-dependent (and dose-limiting) toxicities
- Adverse CNS effects
Serious complication of CMV in HIV patients?
CMV retinitis
What is the broad spectrum antiviral drug?
Foscarnet (pyrophosphate congener)
What is the spectrum of foscarnet?
HSV/VZV/CMV and RNA viruses including HIV
When would Foscarnet be used instead of acyclovir?
If acyclovir resistant-HSV/VZV strains are infectious agent
What are the most commonly used neuraminidase inhibitors?
Oseltamivir
What is oseltamivir used to treat?
Influenza A and B
How do neuraminidase inhibitors work?
Prevent viral release from host cells
When is prophylactic oseltamivir use considered?
Seasonal prevention for high risk populations (Nursing home patients), Post-exposure prophylaxis for family members at high risk for severe disease
What is the optimal treatment window for oseltamivir?
Within 1-2 days of Syx onset
SEs of oseltamivir?
Neuropsyciatric toxicity - when overprescribed
What are the nucleoside reverse transcriptase inhibitors for HIV?
Zidovudine (Retrovir) and Lamivudine
What is the non-nucleoside reverse transcriptase inhibitor used for HIV?
efavirenz
What are the HIV protease inhibitors?
Amprenavir, ritonavir
What are the protease inhibitors for HCV?
Bocepravir, telepravir
What two drugs are used for resistant strains of HIV?
- Fusion inhibitor - enfurvitide
- Integrase inhibitor - raltegravir
What are the side effects of protease inhibitor drugs?
Lipodystrophy syndrome: Major long term adverse effects from class are hyperglycemia, hyperlipidemia, and fat distribution
What is the general strategy for HIV Tx?
Combination Tx with many drugs
What is the most aggressive schema in HAART?
Two NRTIs, a NNRTI, and a protease inhibitor
