As far as I know, there is NOTHING that will stop a flair-up, only things to hopefully slow it down or help prevent the flair-up from starting and that is the disease modifying drugs, like Betaseron, Copaxone,
Rebif, Avonex and the other one that I can never spell....
Wouldn't it be great if scientists finally found something that would knock a flair-up out in it's tracks? The only thing I know of right now, which is not an option at my age, is pregnancy....