Influenza and Flu Drugs

Question 1

Amantadine & Rimantadine

Answer 1

Viral uncoating inhibitors
Inhibits M2 protein (cannot pump protons into the virion)
Used against type A flu
NOT USED anymore b/c of high resistance

Can use amatadine to treat Parkinson’s disease

• can enter CNS
• Stimulates dopamine release

Question 2

Baloxavir Marboxil

Answer 2

Viral Replication Inhibitor
Given as single dose
Inhibits the endonuclease activity of the viral polymerase to prevent viral replication
-endonuclease is critical component to cap-snatching
Side effects: diarrhea bronchitis

Question 3

Oseltamivir

Answer 3

Inhibit viral neuraminidase activity so inhibit cleaving of sialic acid and release of virion
Effective against A and B
resistance can occur
given orally

Question 4

Zanamivir

Answer 4

Inhibit viral neuraminidase activity so inhibit cleaving of sialic acid and release of virion
Effective against A and B
Give via inhalation

Question 5

Peramivir

Answer 5

Inhibit viral neuraminidase activity so inhibit cleaving of sialic acid and release of virion
Effective against A and B
Resistance can occur
Give via IV

Question 6

Influenza virus

Answer 6

Orthomyxoviridae
-ssRNA
enveloped
helical capsid
8 genome segments
3 serotypes
A- most prevalent
B- almost exclusively in humans
C- rare in humans, seen in dogs, pigs

Question 7

Influenza Life Cycle

Answer 7

1. Attachment via sialic acid HA (hemagglutinin) binding
2. Receptor mediated endocytosis
3. Membrane fusion and uncoating in endosomes activated by acidification (M2 protein)
4. Transcription of viral mRNA’s (cap snatching - 1st several RNA residues of host cells removed and used as the 5’ cap of the nascent viral RNA)
5. Replication in the nucleus
6. Assembly and budding from plasma membrane
   - NA (neuraminidase) cleaves sialic acid and allows the influenza virus to leave cell