Antiviral Drugs

Question 1

Zanamivir and Oseltamivir are ____________(guanosine analogs/neuraminidase inhibitors)

Answer 1

Neuraminidase inhibitors

Question 2

Route of administration of Zanamivir is ____________.

Answer 2

Inhalation

Question 3

Route of administration of Oseltamivir is __________.

Answer 3

Oral

Question 4

What are neuraminidase inhibitors used for?

Answer 4

Acute uncomplicated influenza (type A and B) treatment and prophylaxis

Question 5

Oseltamivir is a prodrug that is first metabolized in the liver by _______ (oxidases/esterases)

Answer 5

Esterases

Question 6

Zanamivir and Oseltamivir are both excreted through the ________

Answer 6

Urine

Question 7

What is the function of the viral enzyme neuraminidase?

Answer 7

Neuraminidase is inserted into the host cell membrane for the purpose of releasing newly formed virions

Question 8

Why should Zanamivir be used with caution in patients with asthma or chronic obstructive pulmonary disease?

Answer 8

Irritation of the respiratory tract occurs with Zanamivir. It may also cause bronchospasm.

Question 9

What are the adverse effects of Oseltamivir?

Answer 9

GI discomfort and nausea which can be reduced by taking the drug with food

Question 10

When are antiviral agents for influenza used?

Answer 10

When patients are allergic to vaccine

When outbreak occurs

Question 11

What is the preferred approach to influenza?

Answer 11

Immunization is preferred over antiviral agents

Question 12

What are the names of adamantane derivatives?

Answer 12

Amantidine

Rimantidine

Question 13

What are the adamantane agents are used for?

Answer 13

For the treatment and prophylaxis of influenza A

Question 14

Amantadine and rimantadine inhibit _____ protein of the proton channel of the virus to inhibit the uncoating and replication of the viral RNA in the infected cell.

Answer 14

M2 protein

Question 15

What is the root of administration of adamantane antivirals?

Answer 15

Oral

Question 16

____________ (amantidine/rimantidine) readily crosses the BBB while the other does not.

Answer 16

Amantidine

Question 17

Route of excretion of both adamantane agents is _________

Answer 17

Urine

Question 18

____________(Amantidine/rimantidine) is primarily excreted unchanged in the urine so dosage reduction is needed in renal dysfunction.

Answer 18

Amantidine

Question 19

__________(amantidine/rimantidine) is extensively metabolized by the liver and both the metabolites and the parent drug are eliminated in the ________(urine/feces)

Answer 19

Rimantidine

Urine

Question 20

What are the adverse effects of amantidine?

Answer 20

Insomnia
Dizziness 
Ataxia
Hallucinations (more severe)
Seizures (more severe)

Question 21

___________(amantidine/rimantidine) should be used with caution in patients with psychiatric disorders, cerebral atherosclerosis, renal impairment, or epilepsy.

Answer 21

Amantidine.

Rimantidine has less adverse effects of CNS

Question 22

Adamantane agents adverse effects other than CNS reactions?

Answer 22

GI intolerance
Teratogenic effects (should be used cautiously in pregnancy)

Question 23

Mutations of neuraminidase enzymes are _____(less/more) infective and virulent than the wild type

Answer 23

Less

Question 24

Resistant to adamantane antivirals has occurred due to what kind of change?

Answer 24

Change in one amino acid of M2 matrix protein

Question 25

Ribavirin is _________(neuraminidase inhibitor/guanosine analog)

Answer 25

Guanosine analog

Question 26

What are the uses of ribavirin

Answer 26

Influenza A and B Respiratory syncytial virus Chronic hepatitis C infection

Question 27

What are the route of administration of ribavirin in the following? Influenza A and B Respiratory syncytial virus

Answer 27

Influenza A and B = oral | Respiratory syncytial virus = inhalation

Question 28

Ribavirin is given with ____________ to treat chronic hepatitis C infection.

Answer 28

Interferon alpha

Question 29

Absorption of ribavirin is increased if it is taken with _________

Answer 29

Fatty meal

Question 30

Ribavirin and its metabolites are excreted in ________ (urine/feces)

Answer 30

Urine

Question 31

What are the two major adverse effects of ribavirin

Answer 31

1. Transient hemolytic anemia (with elevated bilirubin) | 2. Teratogenic effects (contraindicated in pregnancy)

Question 32

In what age group and how can respiratory adverse effects occur with ribavirin?

Answer 32

Occurs in Infants | Use of aerosol can lead to respiratory deterioration.

Question 33

How does ribavirin inhibit replication of RNA and DNA viruses?

Answer 33

Ribavirin ———> Ribavirin triphosphate Ribavirin triphosphate does three things. 1. Inhibits the synthesis of guanosine triphosphate 2. Preventing viral mRNA capping 3. Blocking RNA-dependent RNA polymerase

Question 34

What is mRNA capping?

Answer 34

Adding 5’ to the mRNA to stabilise the mRNA.