My doctor allowed me to choose how to take the Mestinon as long as I don't go over 1500mg. I think it was last week that I was having problems with my back muscles and my ribs felt like they were being crushed. I tried increasing my dose by half a pill and felt worse so the next morning I missed a dose and waited for the next dose. I started feeling relief in my back and ribs. So, for the next couple of days I skipped the morning dose, but after a couple of days I started feeling weak again but it was because I wasn't getting enough so one afternoon I increased my dose by 30 mg and felt better. I'm still learning to understand how to react to the changes in my body and sometimes it's not so easy. My antibodies are modulating and I think that's why I'm having so many issues.