I think the problem with Mestinon is the fluctuant nature of the illness. First, no two MG are the same, second, it varies along the day according to outside parameters like temperature and physical activites.
This means that besides a regular intake of Mestinon (every so hours), you may to adjust the dosage to follow your condition. For example, if you feel weak, why not take ONE extra pill? If you feel better afterwards, resume your regular schedule after the extra pill. If not, wait until your condition goes back to "normal" then resume your regular schedule.
Patients who have been taking Mestinon for some time have learned to listen to their body and adjust the intake accordingly.
I take 60 mg normally at 8:30, 9:30,11:30,2:00,5:00 and 8:00 because most of my difficulties are concentrated in the mornings: breakfast, shower, dressing whereas I usually take a little nap in the afternoons...
One more thing, in my opinion, very few patients live a "normal" life only with Mestinon...
Maurice.