Antivirals - Influenza and Hepatitis B

Question 1

4 antiviral drugs for influenza

Answer 1

Amantadine
Rimantadine
Oseltamivir
Zanamivir

Question 2

Spectrum of activity of amantadine

Answer 2

Active only against Influenza A

Question 3

Elimination of amantadine

Answer 3

Urine

Question 4

Dose of amantadine must be reduced in what cases

Answer 4

elderly

renal insufficiency

Question 5

Which anti-influenza agent is a synthetic tricyclic amine?

Answer 5

Amantadine

Question 6

Which anti-influenza agent is an a-methyl derivative?

Answer 6

Rimantadine

Question 7

Spectrum of activity of rimantadine

Answer 7

Active only against influenza A

Question 8

Elimination of rimantadine

Answer 8

Urine

Question 9

Dose of rimantadine must be reduced in what cases

Answer 9

elderly
renal insufficiency
hepatic insufficiency

Question 10

MOA of amantadine and rimantadine

Answer 10

Inhibit uncoating of viral RNA

Question 11

Which channel is blocked by rimantadine and amantadine?

Answer 11

M2 proton ion channel

Question 12

Why are amantadine and rimantadine no longer recommended as anti-influenza drugs?

Answer 12

High rates of resistance

Question 13

ADRs of amantadine and rimantadine

Answer 13

• GI
• CNS
• birth defects
• neurotoxicity

Question 14

What risk is observed when amantadine and rimantadine are administered with antihistamines, anticholinergic drugs, HCTZ, and cotrimoxazole?

Answer 14

Increased neurotoxicity

Question 15

What type of inhibitors are oseltamivir and zanamivir?

Answer 15

Neuraminidase inhibitors

Question 16

What type of analog are oseltamivir and zanamivir?

Answer 16

Sialic acid analog

Question 17

Oseltamivir and zanamivir selectively inhibits what enzymes

Answer 17

Influenza A and B neuraminidases

Question 18

What particular step in viral infection is targeted by oseltamivir and zanamivir?

Answer 18

Release of progeny of influenza virus

Question 19

Route of administration of oseltamivir

Answer 19

Oral

Question 20

Excretion of oseltamivir

Answer 20

Glomerular filtration and tubular secretion

Question 21

What is the effect on the kidney when oseltamivir is increased?

Answer 21

Decreased renal function

Question 22

What is the effect of probenicid to oseltamivir clearance?

Answer 22

Reduced renal clearance

Question 23

ADRs of oseltamivir

Answer 23

• nausea, vomiting, headache
• fatigue, diarrhea
• rash (rare)
• neuropsychiatric events (adults and adolescents)

Question 24

What ADR of oseltamivir is commonly seen in adults and adolescents?

Answer 24

Neuropsychiatric events

Question 25

Route of administration of zanamivir

Answer 25

Inhalation

Question 26

Elimination of zanamivir

Answer 26

Urine

Question 27

2 drugs for hepatitis B infection

Answer 27

Entecavir | Lamivudine

Question 28

What type of analog is entecavir

Answer 28

Guanoside nucleoside analog

Question 29

Entecavir has selective activity against _____ .

Answer 29

HBV polymerase

Question 30

MOA of entecavir

Answer 30

inhibit HBV polymerase

Question 31

Activities of HBV polymerase that are inhibited by entecavir

Answer 31

1. base priming 2. reverse transcription of genomic strand from the progenomic mRNA 3. synthesis of the positive strand DNA

Question 32

Oral bioavailability of entecavir

Answer 32

100%

Question 33

Entecavir should be taken on a ____ stomach.

Answer 33

empty

Question 34

Excretion of entecavir

Answer 34

Glomerular filtration and net tubular secretion

Question 35

Clinical uses of entecavir

Answer 35

- chronic HBV infection | - used as a weak anti-HIV drug

Question 36

What ADR is observed when entecavir is co-administered with drugs that reduce renal function?

Answer 36

Increased serum concentration of entecavir or co-administered drug

Question 37

What type of analog is lamivudine?

Answer 37

Nucleoside analog

Question 38

What is the specific activity of lamivudine?

Answer 38

Inhibit HIV reverse transcriptase and HBV DNA polymerase

Question 39

What is the active form of lamivudine?

Answer 39

Triphosphate form

Question 40

Mechanism of chain termination by lamivudine

Answer 40

Triphosphate form competes for viral DNA

Question 41

True or False: Lamivudine does not bind significantly to plasma proteins and crosses the placenta.

Answer 41

True

Question 42

Elimination of lamivudine

Answer 42

Via the urine unchanged

Question 43

Which HBV agent is recommended for pregnant women?

Answer 43

Lamivudine

Question 44

Clinical uses of lamivudine

Answer 44

- chronic HBV infection in adults and children - HIV in adults - HIV in children greater than or equal to 3 months of age

Question 45

What ADR is expected when lamivudine is co-administered with co-trimoxazole?

Answer 45

Increased bioavailability of lamivudine

Question 46

What is the drug interaction between lamivudine and zalcitabine?

Answer 46

They inhibit the intracellular phosphorylation of each other.