Graves disease!?

ok my older sister have 2 forms of graves disease.. she is 25. i know she is on several medications for the disease but is sketchy on taking them as she is supposed too. my query is since the graves disease already gives her tachycardia (fast heartrate) what can begin to her if i she does a drug like coccaine? what happen was she call me this last weekend when she be out drinking with some friends and told me she have a little cocaine. i am worried that she could hold a serious side effect with already have the graves disease. she made it this time but if she messes with the stuff again can it shoot her suddently?Graves disease!?
I also have Grave's disease. Has your sister have the radioactive iodine yet? When given it is suppose to eradicate part of the thyroid and lower the amount of thyroid surrounded by your blood, reducing the tachycardia. She should really try to get her Graves disease below control if she is going to be living a wild time. I know with a swiftly heart rate cocaine does not mix it can cause heart dud. She may be going thru alot too, not knowing what is going on with her disease, conceivably see about getting her into a support group. It is a time long disease. Because usually after the radioactive idione you go hypothyroid and require thyroid meds for natural life. Hope this helps.
Some of the medcation can rationale a heart attack just on their own similar to Avandia.
Cocaine can cause irregular heart tempo on its own. I think mixing any drugs not prescribed by your doctor is an luck waiting to happen.