Antivirals

Question 1

Docosanol

MOA

Answer 1

22-C saturated alcohol that interferes wth viral fusion step (blocks viral entry)

Question 2

Acyclovir

MOA

Answer 2

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

Question 3

What advantage does valcyclovir have over acyclovir?

Answer 3

Valcyclovir has improved oral bioavailability

Question 4

How could a herpes virus develop resistance to acyclovir?

Answer 4

Delete its thymidine kinase that provides the first phosphorylation for acyclovir

Prevents the acyclovir from being activated

Question 5

Acyclovir

AEs

Answer 5

Malaise
Nausea
GI sx
Headache

At high doses, may precipitate in kidneys and cause renal failure

Question 6

Gancyclovir

Indications

Answer 6

Used in CMV, HHV6 and 8, EBV

Question 7

Gancyclovir

AEs

Answer 7

Bone marrow suppression

Rash
Diarrhea
N/V

Question 8

Foscarnet

MOA

Answer 8

Directly inhibits viral DNA polymerase by inhibiting pyrophosphate binding

Question 9

Foscarnet

AEs

Answer 9

Nephrotoxicity (foscarnet crystals in glomeruli)

Electrolyte abnormalities (K+, Ca2+, Mg2+)

Myelosuppression and anemia

Question 10

Pritelivir

MOA

Answer 10

Helicase-primase inhibitor that halts DNA replication

Question 11

What is the classic treatment for HCV (pre-2010)?

Answer 11

Ribavirin (daily) and weekly injections of pegylated interferon (alpha)

Question 12

Ribavirin

MOA

Answer 12

Depletes GTP pools to block viral RNA polymerase

Question 13

Ribavirin

AEs

Answer 13

Teratogenic

Severe hemolytic anemia

Question 14

Interferon

MOA

Answer 14

Stimulates host antiviral immunity

Question 15

Interferon

AEs

Answer 15

Flu-like symptoms
Depression
Myelosuppression
Drug-induced lupus

Question 16

What are the 3 treatments for chronic HBV?

Answer 16

Pegylated IFN

Entecavir

Tenofovir

Question 17

Entecavir

MOA

Answer 17

Inhibits HBV DNA priming, RT, and DNA polymerase activity

Question 18

Entecavier

AEs

Answer 18

Lactic acidosis

Rebound hepatitis

Question 19

Tenofovir

MOA

Answer 19

Blocks HBV DNA-polymerase after being hydrolyzed to nucleoside analog and phosphorylated to ten-PPP

Question 20

Tenofovir

AEs

Answer 20

GI symptoms
Fatigue
HA
Renal failure

Lactic acidosis

Question 21

Amantidine

MOA

Answer 21

Blocks influenza M2 channel in the virion membrane, preventing the release of its RNA genome from virion

ONLY works against influenza type A

Question 22

Amantidine

AEs

Answer 22

Anxiety
Disorientation
HA

Question 23

NA Inhibitors

List them

Answer 23

Oseltamivir and Zanamivir

Question 24

NA Inhibitors

MOA

Answer 24

Inhibit NA from cleaving the HA from host cell sialic acid

Prevents viral dissemination from infected cells

Question 25

NA Inhibitors

AEs

Answer 25

N/V
Insomnia
Vertigo

Question 26

Why does drug resistance occur more readily with RNA viruses?

Answer 26

There are no RNA-repair mechanisms, causing a huge error rate in RNA-dependent replication

Question 27

What drugs may be used in treatment of RSV?

Answer 27

Palivizumab (mab against viral F protein, needs to be administered before exposure)

Ribavirin (not really much now)