when my husband was first diagnosed in 2012 he was started in Sinemet he did not have any side effects that I remember, about 3 years later he was changed to Stalevo as it acted longer. In the past 2 weeks or so he changed back to Sinemet because the Stalevo has gotten so expensive. Now he is having Diareah and head ache. I am wondering if it is side effects or something else. Anyone else make such changes and have such reactions?