What are the 3 types of influenza?
A, B and C
Briefly Describe the process of viral life cycle
- Virion attaches to neuraminic acid on cell glyocprotein. Virus gains entry via endocytosis
- ATP driven entry of protons into endosome to allow fusion of viral membrane with internal endosomal membrane
- Protons enter virus through M2 ion channel and results in breakdown of viral coat. RNA escapes into host cytoplasm
- RNA uses host transcription mechanisms to form copies of itself
- Virion assembles and buds out of cell. Uses neuramidase on its surface to cleave itself off the host cell
Name 2 M2 ion channel blockers. Which influenza types are they effective against?
Amantadine and rimantadine
Why is rimantidine preferred over amantadine?
Less severe ADRs
How do neuramidase inhibitors work?
Prevent the action of neuramidase which cleaves the virus off the host cell membrane, allowing it to infect other cells
Name 2 neuramidase inhibitors. What type of influenza is neuramidase inhibitors used to treat? How are these drugs taken?
Influenza A and B
Zanamivir (aerosol) and oseltamivir (prodrug oral)
What are some ADRs for neuramidase inhibitors?
GI disturbances, headaches, nose bleeds
Within how many hours is treatment with oseltamivir effective?
Up to 48 hours after symptom onset