Usmle Pharmacology Antivirals

Front 1

Drug of choice for cytomegalic retinitis in immunocompromised patients?

Back 1

Ganciclovir

Front 2

Why is CMV resistant to Acyclovir?

Back 2

CMV is deficient in thymidine kinase, therefore forms triphosphate by another route

Front 3

Describe the action of thymidine kinase (viral) on acyclovir?

Back 3

It phosphorylates acyclovir to monophosphorylated) thus allowing further phosphorylations by host enzymes

Front 4

How does acyclovir inactivate viral DNA polymerase?

Back 4

by being incorporated into the growing viral DNA chain it terminates elongation and binds irreversibly to viral DNA polymerase thus leading to inactivation.

Front 5

The drug of choice for herpes infected cells that divide is?

Back 5

acyclovir

Front 6

Drug similar to ganciclovir but used to treat herpes zoster infections?

Back 6

famciclovir-a prodrug that must be metabolized to penciclovir.

Front 7

This drug is used to treat ganciclovir resistant CMV in patient with HIV?

Back 7

Foscarnet (not a purine or pyrimidine analog. It inhibits viral DNA and RNA polymerases.

Front 8

This drug is a pyrophosphate analog that binds to the pyrophosphate binding site of viral RNA and DNA polymerase leading to inactivation

Back 8

Foscarnet

Front 9

Inhibits influenza neuraminidase

Back 9

Zanamivir and Oseltamivir

Front 10

Inhibits synthesis of guanine nucleotides by competitively inhibiting IMP dehydrogenase

Back 10

Ribavirin

Front 11

Drug of choice for RSV and chronic hepatitis?

Back 11

Ribavirin

Front 12

Blocks viral penetration/uncoating

Back 12

Amantadine

Front 13

This antiviral causes release of dopamine thus having an addition benefit?

Back 13

Amantadine

Front 14

This antiviral causes ataxia, dizziness, and slurred speech? What is an alternative?

Back 14

Amantadine thus use Rimantidine which has less CNS complications

Front 15

This antiviral inhibits viral DNA polymerase when phosphorylated by viral thymidine kinase

Back 15

Acyclovir