Anti-Virals

Question 1

MOA of Acyclovir/Cidofovir?

Answer 1

inhibition of viral DNA polymerase

Question 2

MOA of Amantadine/Rimantadine?

Answer 2

Inhibition of viral entry or uncoating

Question 3

MOA of Ribavirin?

Answer 3

Inhibition of viral nucleic acid synthesis

Question 4

MOA of Oseltamavir/Zanamivir?

Answer 4

Inhibition of release of influenza virus from infected cells

Question 5

How is acyclovir metabolized?

Answer 5

Viral cells (not host) transform acyclovir to its active triphosphate form

Question 6

How is Amantadine metabolized?

Answer 6

Systemic elimination unchanged by glomerular filtration and tubular secretion

Question 7

How is cidofovir activated?

Answer 7

Metabolized via pyrimidine nucleoside monophosphate kinase to mono- & then
diphosphate analogs and finally to the monophosphate-choline

Question 8

How is cidofovir metabolized?

Answer 8

Systemic elimination unchanged by glomerular filtration and tubular secretion

Question 9

How is Oseltamavir activated?

Answer 9

Hepatically metabolized to the carboxylate active form of the drug

Question 10

How is Oseltamavir metabolized?

Answer 10

Systemic elimination by glomerular filtration and tubular secretion

Question 11

How is Ribavirin metabolized?

Answer 11

Undergoes non-CYP metabolism in nucleated cells with systemic elimination of
drug and products in the urine

Question 12

How is Rimantadine metabolized?

Answer 12

Extensive hepatic metabolism with renal elimination of drug & metabolites

Question 13

How is Zanamivir metabolized?

Answer 13

Renally eliminated unchanged

Question 14

AEs of acyclovir?

Answer 14

Headache, nausea, neurotoxicity (confusion, seizures)

Question 15

How to give acyclovir correctly

Answer 15

Maintain hydration to prevent renal precipitation

Use cautiously in renal impairment or with reno-toxic drugs

Question 16

When is amantadine contraindicated?

Answer 16

Contraindicated in narrow angle glaucoma and with breastfeeding

Question 17

BBW of Cidofovir?

Answer 17

Renal impairment/toxicity

Question 18

As of Oseltamavir?

Answer 18

Minimal adverse effects

Potential for fatal neuropsychiatric adverse effects in flu patients; serious skin reaction reported rarely

Question 19

BBW of Ribavirin?

Answer 19

hemolytic anemia & M/F teratogenicity

Question 20

Added AE of Valacyclovir?

Answer 20

Thrombocytopenia

Question 21

AEs of Zanamivir?

Answer 21

Headache, throat/tonsil pain, cough, viral infection

Question 22

Contraindications of Zanamivir?

Answer 22

pulmonary disease – fatal bronchospasm! especially in asthma patients

Question 23

T or F. Amantadine and Rimantadine are good for Flu A AND B

Answer 23

F. Just A

Question 24

When does treatment need to be initiated for effective treatment of Flu?

Answer 24

48 hours maximum

Question 25

If a patient had influenza A and Amantadine was used, what should the physician consider?

Answer 25

- eliminated unchanged in kidneys (renal failure) | - accumulation would exacerbate neurologic toxicity

Question 26

If you give zanamivir to an asthmatic, what else should be given?

Answer 26

pre-treatment with albuterol inhaler

Question 27

AEs of amantadine?

Answer 27

-behavioral changes (seizures, agitation)

Question 28

How does amantadine cause behavioral changes?

Answer 28

alteration of dopamine neurotransmission

Question 29

Behavioral changes from amantadine are more common in which patients?

Answer 29

- seizure disorders - renal insufficiency - advanced age

Question 30

What concurrent drugs can increase risk of behavioral changes from amantadine?

Answer 30

- antihistamines - anticholinergic drugs - HCTZ - Bactrim

Question 31

Acute Amantadine overdose can cause what?

Answer 31

clinical manifestations of anticholinergic activity (GI stasis, urinary retention, dry mouth)

Question 32

Common AE of Amantadine? Very important

Answer 32

livedo reticularis (progression to ilceration possible, but usually resolves with drug withdrawal)