My RB Tex suffered a long time with hyperthyroidism. He lost alot of weight at the end, and I was pretty sad to see the progression. Tex was on two drugs- methimidazole and calcitriol. The methimidazole controlled the thyroid. I don't remember it making him 'sick' as you describe, though. What dose is he on? Have you tried a 1/4 tab of an antacid? Tell me more about the meds...after 10 years of trying to help Tex, we kind of tried out lots of different things.