Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with a doctor.
Without the ability to examine and obtain a history, I can not tell you what the exact cause of the symptoms is. However I will try to provide you with some useful information.
Tilt testing is a form of autonomic testing that assess orthostasis, i.e., how your body adapts hemodynamically to changes in posture. This test is widely used in syncopal workup. The drugs that we ask that patients avoid for at least 48 hours prior to testing are over the counter cold or cough medications, antihistamines (such as benadryl), antidepressants, or diuretics. Additionally, smoking and caffeine should be avoided at least 4 hours to testing. Alcohol should be avoided at least 12-14 hours prior to testing.
In your case, you should also stop the topiramate prior to testing. It has a diuretic effect. You should discuss with your physician if it should be weaned off since it is traditionally an antiepileptic medication. You probably will not be asked to stop the imitrex if you take within 48 hours of the procedure, but you should discuss this with the testing lab. The supplements you mention will likely not need to be stopped.
I would advise you to contact the lab who is performing the tests and ask them what their preferences are. Many labs will have different preferences on what medications should and should not be stopped.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.
Thank you very much for the reply. I did eventually get a call back from the lab. The technician recommended not to start the topiramate and warned me about some OTCs to avoid that are on my profile.
I appreciate the feedback.