The doc wants to take me off of Mestinon to try the Imuran, but I'm afraid that I won't be able to breath without without it. If something is working then why try something else to establish a base line? I may not be able to physically do things I used to but if I can't breath none of that matters. I don't know how Imuran works or if it will help with breathing, but I'm afraid of trying something that might end up disastrous, especially with my family history. Maybe I should talk to the doctor about a back up plan.