I'm sorry that I don't have any advice for you. I take 30mg mestinon 3 times a day with no side effects and I don't even officially have MG. I DesertFlower is right in that you need to constantly keep your neuro informed about the effects that the mestinon is having on you. It's the only way that you'll be able to properly gauge the actual dosage that you need.

My symptoms fluctuate in severity all the time. I go through good periods and bad periods. There are times when I can't even pick up a cup of water and other times in which I can pick up a 10 lb weight. It's very strange and confusing. The problem is there are less good periods than bad. And the good periods are short lived, up to a week at most so far. The bad periods drag on for months on end. I'm best in the mornings and then get weaker and weaker as the day progresses.

Yesterday around mid-day (2-3pm) I couldn't pick up a small bowel of rice (maybe 1lb at most). I was also just beginning to have breathing problems so I took a 30mg Mestinon. A half an hour later I could pick up bag filled with rolls of quarters (about 8-10 lbs) with relative ease. My strength was not a 100% but how can anyone say that this is not a significant strength improvement? When I take the mestinon, within 20-30 minutes I can feel my strength improving.