Thanks for your reply. I have been told not to take over the counter meds for that very reason-- the rebound headaches. I have those and they are the worse. I have had migraines for atleast 20 years now and have seen countless doctors. The one doctor that I had the best success moved out of state. I almost died! I missed her so much but she had my headaches under control for the longest time. Her theory was this. Do not take over the counter meds for anything, sinus problems, headaches or anything. All of these things contribute to the headaches. Also she said that many headaches in women come from fluctuations in their estrogens during the month. Trust me when I say this is true. I had my tubes tied ten years ago but she put me on birth control to level out my estrogen and it really does help. I don't know if she still does it but I know she used to speak all around about headaches in women to other doctors to educate them. She really had a great success rate with her patients with migraines. Unfortuately, when I quit seeing her, I fell back into the migraines. I have a few other medical issues that contribute to my migraines as well. I really hope that the topamax works. It is a very expensive medication. I wish it came in a generic form. I am on alot of other medications. I will tell my sister about the potassium. I really thing that the topamax is going to be the answer for her.