I've been on Mestinon for about 8 years now, when I first started I was on 4 x 60mg and 1 timespan, the timespan did make me rather sick in the mornings, but let me function better. Now I'm on 2 x 60 mg a day. I also have increased salivation, but the effects of the mestinon are better for me than not being on them.
Here is a link to Mestinon that give a good explanation of what it is, and a bit about it.
http://www.mestinon.com/index.jspf