I have been on methimazole for about 5 days now. I still have spikes of blood pressure and pulse and all the other lousy symptoms. I thought the spikes would have at least gotten better by now. Does this medication stop the thyroid from putting out all those hormones that are bothering me? Can you explain why Im not feeling better. I am hyperthyroid. Im on 10mg 2 times a day for a total of 20mg. Im also on atenolol which Ive taken for years now. 50mg in the am, 25 usually in the afternoon and 50mg at night. My head feels messed up inside, I get spikes, hot flashes, shakes inside my abdomen and my legs shake a lot. Probably some other things I didnt mention. When will all this misery stop. I dont knwo what is anxiety and what is panic attacks and what is thyroid. I woke up this am with this terrible stuff. Thanks