During the time when I first started Mestinon I had an extreme runny nose, especially when my neuro had me double my dosage. I found that taking a smaller dose and drinking more water makes this problem go away. More water is the best solution for me for overcoming all of the side effects of mestinon such as runny nose and excessive saliva.

Be sure to let your doctor know about this. I hope you are not allergic to Mestinon, but it is a possibility.