It sounds like the Mestinon can work a bit differently for everyone. I've been on the medication for a little over a month. I'm taking 60 mg every 5-6 hours. I was seeing a small improvement in my double vision. In fact, about 10 days ago I noticed that I could actually read a magazine, without my prism glasses, with just minimal double vision. The very next day my double vision was horrible--back to where it was before I had even started the Mestinon.

It makes me wonder if my dose is too high or not enough. I don't go back to my ophthalmologist for several more weeks, then a visit to the neurologist after that. I'm anxious to see the neurologist again to talk about more long range plans. Right now I just have a "working diagnosis" of MG. I had a SFEMG done 7 years ago just when symptoms started. It was negative at that time. I'm wondering if redoing the SFEMG now might yield different results? Last antibody test was about 4-5 years ago, and MUSK was 4 years ago. All negative at the time. Can antibody tests change over time?