Does Madopar knock you out?

Hi, my mother is Madopar, has been for a decade but it seems to knock her out, ie makes her very drowsy. She is on a low dosage, as she is advanced now, but it has never had a 'pick me up' effect on her. She is on slow release, to minimise this effect, but I just wondered if she is actually allergic to the stuff and might she be better off with Sinemet? Is there another kind of levadopa she might use?

It gets to the point where she can be quite with it, almost, then we give her the pill and she 'hits a wall.' She also is 'gurning' a lot, ie pulling yawning faces. The drug seems to be a necessary evil at times.