mama, do you see a general practice neurologist or a movement disorder specialist? Is this the only neurologist you have ever seen for your PD?
Have you discussed this possible medication interaction with a Pharmacist?
It is a pharmacist's job to help with drug interaction issues and to make suggestions for alternate medications your doctor can use.
I can see from your words how distressing your situation must be.
Hopefully someone has dealt with this issue and will reply here.