Influenza arv

Question 1

What is the difference between influenza a and b

Answer 1

Influenza A has M2 protein ,which act as an ion channel extending through the envelope and has an important role in the penetration and release of viral RNA into host cell whereas Influenza B contain different protein and are therefore not sensitive to M2 protein inhibitors

Question 2

What are the similarities between Influenza A and B

Answer 2

They both contain glycoproteins Neuraminidase and Hemagglutinin ,which are necessary for attachment of virus to host cell

Question 3

Give the 2 types of ART for influenza

Answer 3

1. Neuraminidase inhibitors
   * Oseltamivir
   * Zanamivir
2. M2 protein inhibitors
   * Amantadine
   * Rimantadine

Question 4

Discuss the MOA of Amantadine

Answer 4

> M2 protein inhibitor and thus used for influenza A
It blocks M2 which acts as a channel for hydrogen ions
It also prevents the uncoating as well as viral assembly

M2 channel is responsible for the fusion of the viral membrane with the cell membrane to form the endosome

Question 5

What are the pharmacokinetics of Amantadine

Answer 5

> Well absorbed after oral administration
Crosses BBB
Excreted in the urine and dosage adjustment is requirement with renal impairment

Question 6

Amantadine contraindications

Answer 6

> Should not be used in CNS disease( except in Parkinson disease ) and Epilepsy

Question 7

How does Amantadine assist in Parkinson disease

Answer 7

> Found by chance to have anti-Parkinson properties
They promote the release of dopamine from synaptic terminals
Reduce the up-take of dopamine by pre-synaptic neurons
Used in early disease and effects are short lived

Question 8

Discuss the pharmacokinetics of oseltamivir

Answer 8

> Available as capsule and suspension
Neuraminidase inhibitor
Should be used in individuals older than 1 years
Used to reduce symptoms ,severity and duration of illness
Can be taken with/without food
It is converted to its metabolic form hepatic esterase oseltamivir carboxylase
Metabolism is not affected by P450 inhibitors / inducers
Excreted unchanged in urine

Question 9

Discuss zanamivir

Answer 9

> Neuraminidase inhibitor
Administered via diskhaler by inhalation or intranasal
Excreted by unchanged in urine