Carbidopa / levodopa
"Diag 2010 at 46yo.  Currently on year 6-7 of taking this combination of drugs.  Still doing good but have noticed more off time as the years/months go by.  I know the 10 year time window of losing its effectiveness is fast approaching for me. 

Generics are not all created equal.  You need to try every mfg for a few months to see which one works for you.  For me the only brand that works is mfg by Mayne Pharma (formerly Teva).  The other mfg: on one I can never get stabalized (to much/too little in a pill) the other one gives me night terrors."