Wow, I’m really impressed that you have no  symptoms from either the prednisone or the Mestinon.  You are really lucky.  Currently I am on 5mg Prednisone and 180 mg Mestinon ER (extended release).  I take the prednisone in the a.m. and the Mestinon a little while before bedtime (around 7 p.m.).  The prednisone causes increased appetite (with weight gain), acne in various body sites, and some other minor issues.  The Mestinon causes significant G.I. problems, especially in the morning (diarrhea, constipation, etc.), muscle cramping and twitching, and night sweats.  The good news is that I’m currently (for the past 4 months) in remission for my MG issues, so the trade-off is definitely worth it.  Again, you are really lucky not to have any symptoms.  Good luck!

Mike