I took Norpace for a few years. It does cause constipation and also caused me to have dry mouth and urinary retention. There is a drug called mestinon which treats myesthenia gravis which is supposed to help with the side effects from Norpace. I never tried it myself, but it is something worth asking about. There are also other anti-arrythmic drugs which may do the same job but allow you to feel better. The problem is that anti-arrythmics are all very strong drugs and often come at the price of side effects.