We found the Sinemet CR didn't work for my husband.
The neurologist said he believed little and often was the best way and so my husband takes Sinemet every 2 hours and when we go out and his dose starts wearing off he takes Madopar dispersible with a couple of mouthfuls of water.
It works in about 10 mins and keeps him going until his next dose is due.
He also takes the Madopar before and after a large meal as the food stops his Sinemet being absorbed.
We have found it invaluable to rescue him In a variety of social situations such as meals out, cinema visits, unexpectedly late situations.
? Worth a try.