I have not been posting for some time.
Yes, I have taken Comtan (entacapone). I took it for 2 years and now I take Stalevo 150, whic contains 200 mg of Comtan per tablet.
Comtan has no anti-parkinson action alone. It inhibirts 1 of the 2 enzymes which metabolizes dopamine and levodopa (contained in Sinamet) thus extending the amount of levodopa that is available to cross the blood-brain barrier; this extends the time
dopamine remains active in the brain (substantia nigra and striatum). There is an increased in dopamine elsewhere in the body, whitch causes side effects.
Side effects are more severe at first (usually). To reduce the Sinemet dose reduces
these side effects.
I think Comtan is GOOD drug to extend the duration of Sinemet.