David, while I defer to others far more erudite on the matter of meds, you might be interested to know that a surprising number of PWP [people with Parkinson's] had a frozen shoulder similar to yours [and mine]. I think we firmly established it as a bonafide PD early symptom here on this List about a year or so ago. You may have noticed some distractions now on the list; if you don't get a response on your meds question, ask again.