Jcrum
You ask about others experience of Madopar, i have been on it about 4 years. It had a positive effect almost immediately. I did not have any of the problems you describe. But my starting dose was 125mg twice daily ie 200mg L Dopa in 24 hours and I stayed at that amount for some months. Sounds like your husband was on 450mg L Dopa daily and he reached this amount within a week.
Now he has stopped the dopamine challenge but he may begin treatment on these or similar meds. When/if he does start meds can i say that my experience has been mostly OK but i always go for introducing a small amount and slowly. I figure it takes quite some time for my body to adjust to meds and Ill be a lifetime on them so why rush.