Anti

Question 1

Acyclovir

Answer 1

Mechanism:
Structural analog of deoxyguanosine
viral DNA polymerase adds and causes chain termination

resistance:
Mutations in TK or viral polymerase

Toxicity: Well tolerated

Use:
HCV
VZV

Oral bioav.
Valacyclovir has higher bioavailability

Question 2

Foscarnet

Answer 2

Mechanism:
Binds to pyrophosphate site of viral polymerase
x100 viral > human

Resistance:
mutation in polymerase

Toxicity:
Hepatoxicity, but reversible
hypocalcemia/CNS toxic

Use:
HSV/CMV that is acyclovir resistant

Question 3

Tenofovir

Answer 3

Mechanism:
nucleoside/nucleotide reverse transcriptase (RT) inhibitor (NRTI)
competes with dATP and causes chain termination

Resistance:
mutation in RT

Toxicity:
Hepatotoxicity

Use
1st line of defense for HIV
often used with efavirenz
HBV

orally active, penetrates CNS

Question 4

Efavirenz

Answer 4

Mechanism:
Non-nucleoside reverse transcriptase inhibitor NNRTI
does not bind to active site like NRTI (non-competitive)

Resistance:
mutations to RTase

Toxicity:
CNS effects such as insomnia, confusion, and depression

Use
1st line of defense of HIV
used with tenofovir

orally active

Question 5

Darunavir, Ritonavir

Answer 5

Mechanism:
HIV-1 protease inhibitor
prevent processing precursor polyproteins into final structure proteins into virions

Resistance:
pol gene mutations
pol gene encodes protease

Toxicity:
GI effects
long term use effects carb and lipid metabolism

Use
Combined with HIV RTase

orally active
*Ritonavir –> inhibits CyP3A4 which boosts HIV and HCV protease inhibitors

Question 6

Raltegravir

Answer 6

Mechanism:
inhibits viral DNA from integrating into host DNA

Resistance:
mutations to integrase

Toxicity:
well tolerated

Use
in combination to other 1st line HIV drugs
orally active

Question 7

Maraviroc

Answer 7

Mechanism:
CCR5 coreceptor on CD4/macrophage
prevents binding of gp120 to allow HIV viral entry

Resistance:
mutation of CCR5 receptor

Toxicity:
well tolerated, but can cause CNS effects

Use
after 1st line of HIV viral drugs fail,
*CXCRY coreceptor is not inhibited
orally active

Question 8

Enfuvirtide

Answer 8

Mechanism:
binds to gp41 of viral envelope preventing fusion of viral and cellular envelope

Resistance:
mutation of gp41

Toxicity:
injection site symptoms

Use
alternative treatment multiviral resistance (HIV)
injection

Question 9

interferon

Answer 9

Mechanism:
act through Jak/Stat pathway affecting gene transcription and cell signaling

Resistance:

Toxicity:
fever, fatigue, marrow suppression, depression, flu-like symptoms

Use
HPV, Hep B/C, HSV III, treatment for all alien viruses

Question 10

Sofosbuvir

Answer 10

Mechanism:
HCV NS5B RNA-dependent polymerase inhibitor

Use
very expensive
used in combo with ledipasvir
HCV

Question 11

Ledipasvir

Answer 11

Mechanism:
interferes with NS5A protein needed for viral replication in HCV

Use
very expensive
used in combination of sofosbuvir
HCV

Question 12

Paritaprevir

Answer 12

Mechanism:
Hep C protease inhibitor

Use
ritonavir boosts this PI effectiveness

Question 13

Oseltamivir

Answer 13

Mechanism:
inhibit viral neuraminidase to prevent release of infections particles

Resistance:
mutations to neuraminidase

Use
reduce duration of flu especially if used 24 hours of onset,

prophylactic treatment