My husband got them from Walgreens, they really help the headaches, he still gets them but not as bad and he doesnt throw up as often. Yes they are just like migranes. I am not sure what brand of IVig your son is getting, we changes to the brand flebogamma, he seams to have less side effects. My son cannot take gammar gobulin, it takes to long because it is so thick, the flebo only take 2 1/2 to 3 hours. My son gets his 20th tx next week, he has been doing much better this winter, that is when it seams to not last as long.
Keep me informed let me know if you would like to email me.