What Causes Dizziness While Suffering From Meniere S Disease?

Yes I have menieres . Been thru all test and hearing test Lately I ve had vertigo attacks went to my primary Dr. Yesterday with dizziness and nausea. The meclazine just don t cut it. He prescribed a pill hygroton 25 my chlorthalidone 25 tab sun. Took the first pill at 3 pclock yesterday and within a few hours the vertigo went away. Took a pill this morning and so far so good. I m just curious as to what you think thanks Shirley