Preventative name help

I go back and see my neuro tomorrow and I'd like to ask to try a preventative to help with the storm fronts. I know there's a common one, but I can't remember the name of it for the life of me. I need to know the name so I DON'T get it, as it's a sulfa drug and I'm allergic to those. Thank you to anyone who's replies, I'd try to search myself, but I'm really struggling to type this and the thought of a drawn out search scares me right now.

sorry cant help you there, hope app goes ok though.