Can getting a refill of an old prescription make you drowsier when first refilled than later on taking it...example topomax and clariten for headache?

Taking too much?: I'm not sure I am understanding your problem, but it's possible that you used to take topamax (topiramate) and stopped, but now you are taking it again-- you typically cannot simply start back on the same dose you were on before.Topamax (topiramate) can be extremely sedating--should start with the lowest dose for at least a week or 2 and then very slowly and gradually increase to the dose that helps your headaches.