I have never heard of Imuran. What does it treat? I'm on Mestonin three times a day (60mg). I was just to my arthritis doctor and found out I do have a form of arthritis. They are just waiting for the CCP blood test results to come back. If it comes back postive I have the beginning of Rheumatoid arthritis. If negative, it's psoriatic arthritis. I'm thinking I have the later, because I have no symptoms of RA. I'm always stiff at night and my neck is always on fire and stiff and hurts. This on top of having MG. Life is just peachy. Guess what, if I have psoriatic arthritis, the best thing you can do is exercise. How do you do that when your muscles tire out so quick??????