Seems like an L-dopa patch would solve this problem: no need for carbidopa since it's not being taken orally.

We have struggled for years with how to take a B vit. supplement without messing up the meds. Even drinking a Vitamin Water (which has B in it) has the effect, for us, of making our drugs even less effective than they already are. If anyone has any suggestions on how to take a B vitamin supplement while you are also having to take sinement/generic version, please share with us all.

B is critical: they have found in nursing homes a staggering majority of patients were deficient in B vitamins. A great many improved when given B (I'm not saying the patients threw away their canes and jumped out of their wheelchairs, but there was improvement, significantly of the cognitive variety). Of course, this is not a hot topic for pharma