Like Dar, 50 mg is the right dosage for me too. I actually went all the way up to 100 mg as one neuro prescribed and the side effects were horrible...my hands and feet felt like they were constantly asleep, I was beyond "stupid", the nausea was horrible, I had intense weight loss (so bad I went back to a doctor who put me on another pill to counteract the weight loss)...at 100 mg I would basically take the pill and go to bed b/c the side effects were so bad. At 50 mg some of the side effects were still there at first (though not ever as intense), and now the only side effect I have is the dry mouth. You are supposed to drink LOTS of water on topamax, b/c topamax does give dry mouth and be careful when you are outside b/c topamaz affects the body's ability to cool itself so you overheat more quickly (something that may not affect you where you are, but in AZ my doctor warned me about it right away). I didn't ever have a yellow tongue...something you might want to ask your doctor about. I know 100 mg is the recommended dosage for migraine patients, so many doctors aim everyone towards that mark. The bad thing is that means a 5'4 110 lb woman is being given the same dosage as a 6'0 220 lb man. Doesn't make sense to me (but thats just me *smile*). Talk with your doctor about your symptoms and concerns about continuing to increase your dosage.
Good luck! I hope you get some pain relief soon!