Antivirals

Question 1

M2 ion channel blockers:
examples
method of action
treatment use
ADRs

Answer 1

e.g. Amantadine, Rimantadine (tricyclic primary amines)

block M2 channels on viral surface
preventing protons entering virus and lowering pH to allow uncoating

limited to treatment of Influenza A

ADRs: dizziness, GI disturbances, hypotension, CNS effects (confusion, insomnia)
Rimantadine has less side effects

Question 2

Neuraminidase inhibitors:
examples
method of action
treatment use
ADRs

Answer 2

e.g.
Zanamivir: low bioavailibility so given as aerosol (treatment, no prophylaxis)
Oseltamivir (Tamiflu): a prodrug, so higher bioavailibility and given orally (treatment & prophylaxis)

block action of neuraminidase, preventing virus release from host cells (breaking bonds that form between cell membrane & virus)

can be used to treat both Influenza A & B

ADRs: GI disturbances, headaches, epistaxis

Question 3

what are the two main antiviral agents

Answer 3

M2 ion channel blockers
Neuraminidase inhibitors

more available for treatment of DNA viruses over RNA viruses