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.