Antivirals Flashcards
Docosanol
MOA
22-C saturated alcohol that interferes wth viral fusion step (blocks viral entry)
Acyclovir
MOA
Gets phosphorylated by viral kinase, then phosphorylated two more times by cellular kinase
Lacks a 3’-OH group, so when it gets incorporated in viral DNA replication, the process is halted
What advantage does valcyclovir have over acyclovir?
Valcyclovir has improved oral bioavailability
How could a herpes virus develop resistance to acyclovir?
Delete its thymidine kinase that provides the first phosphorylation for acyclovir
Prevents the acyclovir from being activated
Acyclovir
AEs
Malaise
Nausea
GI sx
Headache
At high doses, may precipitate in kidneys and cause renal failure
Gancyclovir
Indications
Used in CMV, HHV6 and 8, EBV
Gancyclovir
AEs
Bone marrow suppression
Rash
Diarrhea
N/V
Foscarnet
MOA
Directly inhibits viral DNA polymerase by inhibiting pyrophosphate binding
Foscarnet
AEs
Nephrotoxicity (foscarnet crystals in glomeruli)
Electrolyte abnormalities (K+, Ca2+, Mg2+)
Myelosuppression and anemia
Pritelivir
MOA
Helicase-primase inhibitor that halts DNA replication
What is the classic treatment for HCV (pre-2010)?
Ribavirin (daily) and weekly injections of pegylated interferon (alpha)
Ribavirin
MOA
Depletes GTP pools to block viral RNA polymerase
Ribavirin
AEs
Teratogenic
Severe hemolytic anemia
Interferon
MOA
Stimulates host antiviral immunity
Interferon
AEs
Flu-like symptoms
Depression
Myelosuppression
Drug-induced lupus
What are the 3 treatments for chronic HBV?
Pegylated IFN
Entecavir
Tenofovir
Entecavir
MOA
Inhibits HBV DNA priming, RT, and DNA polymerase activity
Entecavier
AEs
Lactic acidosis
Rebound hepatitis
Tenofovir
MOA
Blocks HBV DNA-polymerase after being hydrolyzed to nucleoside analog and phosphorylated to ten-PPP
Tenofovir
AEs
GI symptoms
Fatigue
HA
Renal failure
Lactic acidosis
Amantidine
MOA
Blocks influenza M2 channel in the virion membrane, preventing the release of its RNA genome from virion
ONLY works against influenza type A
Amantidine
AEs
Anxiety
Disorientation
HA
NA Inhibitors
List them
Oseltamivir and Zanamivir
NA Inhibitors
MOA
Inhibit NA from cleaving the HA from host cell sialic acid
Prevents viral dissemination from infected cells
NA Inhibitors
AEs
N/V
Insomnia
Vertigo
Why does drug resistance occur more readily with RNA viruses?
There are no RNA-repair mechanisms, causing a huge error rate in RNA-dependent replication
What drugs may be used in treatment of RSV?
Palivizumab (mab against viral F protein, needs to be administered before exposure)
Ribavirin (not really much now)
