anub,
Patients should never just up an stop their medications. If they feel they are taking too many medicines, they should discuss that with their physician. Many times, patients can decrease the medicines they take, if they just discuss their options.
In this case, stopping his blood thinner is probably not a great idea. Also, the thyroid medication is another that should probably be continued.
But, this is something that his physician should know about immediately. You should also try to get him to talk to his doctor. Some of the medicines may be able to be stopped. But, some, by stopping them, may put him a greater risk of having another stroke.
However, it is the patient's right to refuse medicine. As long as they understand the ramifications of doing so.
Good luck.