Shift flarex fin?

I can’t tell what “Shift flarex fin” refers to from that wording alone.

Did you mean one of these?
- A medication name (for example, “flarex” might be a brand name), and you’re asking to “shift” to a different one
- “Shifting” between two drugs (e.g., switching treatments) and you’re asking what changes
- A specific product or instruction phrase used in a document, app, or device

If you share:
1) the full phrase as written (including any punctuation),
2) where you saw it (prescription label, website, insurance letter, etc.), and
3) what country you’re in,
I can give a precise answer.