Antivirals Flashcards Preview

STEP 1 Pharm > Antivirals > Flashcards

Flashcards in Antivirals Deck (24):
1

Zanamivir/oseltamivir

Block neuraminidase. Decreases release of progeny. Used to treat influenza A and B

2

Ribavirin

Inhibits synthesis of guanine nucleotides by inhibiting inosine monophosphate dehydrogenase.

Used for RSV, hepatitis C (chronic)

3

Ribavirin toxicity

Severe teratogen, hemolytic anemia.

4

Acyclovir, famciclovir, valacyclovir

Must be phosphorylated to be active. Phosphorylated in HSV/VZV by thymidine kinase. Guanosine analog. Preferentially inhibits DNA polymerase via chain termination.
Few adverse effects.

Resistance if thymidine kinase mutated.

Used in HSV and VZV. Weak activity against EBV.

Valacyclovir is a prodrug and has better oral bioavailability

5

Toxicity of acyclovir, famciclovir, valacyclovir?

Obstructive crystalline nephropathy and acute renal failure if not hydrated.

6

Ganciclovir

5'monophosphate formed by CMV viral kinase. Guanosine analog. Triphosphate formed by cellular kinases. Inhibits DNA polymerase.

Use in CMV.

7

Ganciclovir toxicity

Leukopenia, neutropenia, thrombocytopenia, renal toxicity. Much more toxic to host enzymes than acyclovir.

8

Foscarnet

Pyrophosphate analog
Viral DNA polymerase inhibitor that binds to the pyrophosphate binding site of the enzyme. Does not require activation by viral kinase.

Used in CMV retinitis or when CMV has UL97 mutation.

9

Foscarnet toxicity

Nephrotoxicity

10

Cidofovir

Preferentially inhibits viral DNA polymerase. Does not require phosphorylation by viral kinases.

Used in CMV retinitis in immunocompromised or in acyclovir resistant HSV.

11

Cidofovir toxicity

Severely nephrotoxic so administer with saline and probenecid.

12

HAART

Initiated when patients present with AIDS defining illness or low CD4

13

Protease inhibitors

End in -navir (atazanavir, darunavir, indinavir, etc).

Assembly of virions depends on HIV protease (pol), which cleaves polypeptide into functional parts).

14

Ritonavir advantage

Inhibits CYP450 so can boost drug concentrations

15

NRTIs

Abacavir, didanosine, emtracitabine, lamivudine, stavudine, zidovudine, tenofovir.

(-vudine mostly)

Mostly nucleosides and must be phosphorylated to be active

16

Which NRTI is a nucleotide and doesn't need to be phosphorylated to be active?

Tenofovir.

17

NRTIs side effects

Bone marrow suppression, peripheral neuropathy, pancreatitis

18

NNRTIs

Efavirinz, nevirapine, delavirdine

Bind to reverse transcriptase at different site than NRTIs, do not require phosphorylation.

Rash/hepatotoxicity/VIVID dreams

19

Raltegravir

Integrase inhibitor, prevents integration of HIV genome into host cell chromosomes. Can cause hypercholesterolemia.

20

Fusion inhibitors

Maraviroc, enfuviratide.

Enfuviritide blocks GP41, inhibiting entry

Maraviroc binds CCR-5 on t-cell/monocytes and inhibits interaction with GP120.

21

Interferons

Glycoproteins normally synthesized by virus infected cells.

22

IFN a use

used in chronic hepatitis B and C, KS, hairy cell leukemia, condyloma accuminatum, renal cell carcinoma, malignant melanoma

23

IFN b use

MS

24

IFN gamma use

Chronic granulomatous disease