Exam 3: Antivirals Flashcards
What are the 3 antivirals for HSV/VZV?
Acyclovir, valacyclovir, and docosanol
What are the 3 antivirals used for influenza?
Oseltamivir, zanamivir, and baloxavir
What are the 3 antivirals used for Hepatitis B?
Tenofovir, entecavir, and lamivudine
What are the 4 antivirals used for CMV/Herpes?
Ganciclovir, valganciclovir, Foscarnet, and Cidofovir
What is the antiviral used for RSV?
Ribavirin
What are the 2 antivirals used for Hep C?
Sofosbuvir/ledipasvir and Sofosbuvir/velpatasvir
What is the DOC for HSV/VZV?
Acyclovir
What is the MOA of acyclovir?
Phosphorylated/activated by viral thymidine kinase in infected cells
Inhibits DNA polymerase by competing with dGTP
How does resistance to Acyclovir develop?
Decrease in thymidine kinase
What are the adverse effects of acyclovir?
- Generally well tolerated because drug is mostly concentrated within virus.
- Nephrotoxicity with high IV doses (hydration is very important)
- Safe in pregnancy
What is the MOA of Docosanol (abreva)?
Inhibits viral fusion to host plasma membrane so the virus cannot get into the cell
What is docosanol used for?
OTC and topical for cold sores/herpes simplex.
What is the MOA of Ganciclovir/valgancilovir?
Phosphorylated/activated by viral kinases in infected cells
Inhibits DNA polymerase
What is the DOC for CMV?
Ganciclovir
What are the toxicities associated with ganciclovir/valganciclovir?
- Myelosuppresion: Leukopenia, neutropenia, and thrombocytopenia
- CNS effects: headache, confusion, seizures
What is the MOA of foscarnet?
Directly inhibits DNA and RNA polymerase and reverse transcriptase. Does not require phosphorylation for activity
What kind of toxicity do all parental antivirals have? How should you combat this?
- They all are renal toxic
- Combated with aggressive hydration
How is CMV encephalitis treated?
Foscarnet + ganciclovir
How is CMV retinitis treated?
- Oral, IV, or ocular implant ganciclovir (replace ocular implant every 5-8 months)
- If ganciclovir resistant, treat with foscarnet
What is the MOA of cidofovir?
- Inhibits viral DNA polymerase
- Does not require phosphorylation for activity
Are are the toxicities associated with Cidofovir?
-Dose dependent nephrotoxicity
What is the MOA of Oseltamivir/zanamivir?
Neuraminidase inhibitors, blocks the release of the virus from cells
What are oseltamivir/zanamivir used to treat?
-Influenza A and B (start within 48 of symptom onset)
Who are oseltamivir and zanamivir approved for?
- Oseltamavir: oral, approved for patients >1 year
- Zanamavir: Nasal or oral inhaler, approved for patients > 7 years
What is the MOA of Baloxavir Marboxil (XoFluza)?
-Endonuclease activity of the PA protein, the drug prevents viral gene transcription and ultimately viral replication
What is the use of Baloxavir Marboxil?
- Active against influenza A and B if started within 48 hours
- Approved for > 12 years, single dose
What is the MOA of Ribavirin?
- Inhibits RNA polymerase and synthesis of GTP
- Phosphorylated by host enzymes
What is Ribavirin used for?
How can it be administed?
- RSV (aerosol) and hepatitis C
- Aerosol, IV, Oral
What are the toxicities associated with ribavirin?
- Oral: Dose dependent hemolytic anemia
- Aerosol: Respiratory depression, cardiac arrest, hypertension
- IV: Psychiatric, depression, suicide
Extremely teratogenic, do no conceive for at least 6 months after exposure to drug
What is the DOC for hepatitis B?
Tenofovir
What is the MOA for Tenofovir?
Inhibits HBV DNA polymerase; reverse transcriptase inhibitor also used for HIV
What is the MOA of Entevcavir?
Inhibits HBV DNA polymerase
What is the MOA of Lamivudine?
Inhibits HBV polymerase
What two hepatitis B drugs have a good safety profile, even in those with advanced disease?
Tenofovir and entecavir
What is the MOA of sofosbuvir?
Inhibits viral NS5B RNA polymerase, blocking replication of HCV when the uridine analogue is incorporated, causing termination
What is the MOA of Ledipasvir/Velpatasvir?
Inhibits HCV NS5A protein and may prevent phosphorylation and replication
