Antiviral Drugs Flashcards

1
Q

Zanamivir, Oseltamivir

A

Influenza drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ribavirin

A

RSV, Hep C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Acyclovir

A

Herpes viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ganciclovir, Foscarnet, Cidofivir

A

CMV drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Interferon Tx

A

Viral infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Zanamivir/Osteltamivir (Tami-flu)

A

Neuraminidase inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Neuraminidase is

A

enzyme that cleaves sialic acid from glycoproteins

-require for exit from cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Zanamivir/Osteltamivir (Tami-flu) must be administered w/n what time frame to be effective?

A

48 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

DNA/RNA polymerases work by

A

splits off two phosphates from nucleotriphosphates

uses remaining phosphate to form backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a mechanism of resistance towards RNA/DNA polymerase inhibitors?

A

Viral kinase mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ribavirin mimics

A

Guanosine

-Has a different base attached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ribavirin is triphosphorylated by

A

Cellular kinases within infected cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ribavirin inhibits

A

RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What other enzyme besides RNA polymerase does Ribavirin inhibit?

A

Inhibits IMP dehydrogenase

  • ribavirin mimics inosine monophosphate (biochemical intermediate that gets converted to guanosine nucleotides)
  • decreases guanosine nucleotides available
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two main uses of Ribavirin?

A

Severe RSV Tx

Combined with interferon to treat Hep C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is key S/E of Ribavirin?

A

Hemolytic Anemia

-Drug accumulates in RBCs and depletes phosphate pool, causing ATP deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Can you give Ribavirin to pregnant women?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Acyclovir

A

Inhibits herpes DNA polymerase
Mimics guanosine
Acyclovir does not have a ribose sugar (O instead of OH)

19
Q

Acyclovir has a targeted effect (only works in effective cells) b/c

A

Acyclovir must be phosphorylated by herpes virus thymidine kinase
Cell enzymes converted acyclovir monophosphate into triphosphate.

20
Q

Acyclovir mimics what to inhibit viral DNA polymerase?

A

deoxyguanosine triphosphate (dGTP)

21
Q

Viruses develop resistance to Acyclovir by

A

decreasing viral thymidine kinase
altering viral thymidine kinase
altering viral DNA polymerase

22
Q

Famciclovir

A

Similar MOA to Acyclovir

Has a longer half-life so lower dose can be used

23
Q

Valacyclovir

A

Pro-drug converted to acyclovir

-Increased bioavailability so lower dose can be used

24
Q

Acyclovir administered by IV can cause

A

Nephrotoxicity

  • Crystallizes in urine
  • Administer with IV fluids
25
Q

HSV-1, HSV-2, and VZV tx

A

Acyclovir

26
Q

Acyclovir is not effective for CMV and EBV (also herpes viruses) because

A

They have a different viral kinase that cannot phosphorylate Acyclovir

27
Q

Tx for genital herpes, oral herpes, herpes encephalitis, herpes zoster

A

Acyclovir

28
Q

CMV infections are a big problem in

A

immunocompromised patients

29
Q

Ganciclovir, Foscarnet, Cidofivir

A

CMV drugs

-Inhibit CMV DNA Polymerase

30
Q

Ganciclovir

A

Similar MOA to Acyclovir

-mimics guanosine

31
Q

Major toxicity of Ganciclovir

A

Bone marrow suppression, especially leukopenia

Also inhibits bone marrow DNA polymerase

32
Q

Valganciclovir

A

Pro-drug that is converted to Ganciclovir

Better bioavailability

33
Q

Ganciclovir is administered by IV due to

A

Poor bioavailability

34
Q

If Ganciclovir must be administered orally for CMV infection,

A

Pt is given its pro-drug, Ganciclovir

35
Q

Foscarnet

A

Pyrophosphate Analog

  • Mimics phosphate group
  • DNA cannot cleave phosphate groups off nucleotide
  • Results in chain termination
36
Q

When is Foscarnet used?

A

CMV Tx when Ganciclovir fails

HSV/VSV Tx when there is resistance to Acyclovir

37
Q

Main limiting S/E of Foscarnet

A

nephrotoxicity

38
Q

Pts on Foscarnet must have electrolytes monitored b/c

A

Foscarnet chelates calcium

  • Causes hypocalcemia
  • Renal wasting of magnesium induced (hypomagnesaemia)
  • Resulting seizures
39
Q

Cidofovir

A

CMV drug
Cytidine analog
Viral DNA polymerase inhibitor

40
Q

Cidofovir undergoes phosphorylation by

A

Cellular kinase (not viral kinase)

41
Q

What is main use of Cidofovir?

A

CMV retinitis

42
Q

What is the main toxicity due to Cidofovir?

A

Renal Failure

  • Cidofovir is bound by anion transporter in proximal tubule, resulting in high concentrations in the renal cortex
  • Co-administer with saline to flush kidneys
  • Use probenecid (gout drug) to block Cidofovir accumulation in tubular cells
43
Q

Interferons

A

Used for anti-viral therapy
Cytokines
Glycoproteins synthesized by infected cells and lymphocytes
Numerous immunomodulatory effects

44
Q

Interferon alpha primes cells to fight against

A

Hep B & C

HHV-8 (causes Kaposi’s sarcoma)