copy: Which medications are right for me? Medications that are effective for one person with Parkinson's disease, may not work well for another person. The best way for a person to identify the right medications is through an evaluation by a doctor or nurse practitioner who is knowledgeable about Parkinson's disease. Several general comments may be helpful in providing general background. For an individual with the first symptoms of Parkinson's disease (for example, a mild tremor in an arm or stiffness in a leg), no medication may be necessary. Mild intermittent symptoms (particularly when it involves the non-dominant arm) may not limit activity. At this early stage, adequate rest, a balanced diet, and an exercise program that emphasizes range of motion may be the most appropriate treatments. Over time, people with Parkinson's disease note worsening of symptoms. Common symptoms that may limit activity include: tremor, slowness, and stiffness. The threshold for beginning treatment varies considerably between individuals. When starting medical treatment for Parkinson's disease, it is important for people to have a realistic expectation about the degree of improvement to expect from medical treatment. For most, an improvement of 20-40% is typical. If tremor of a limb becomes a troubling symptom, treatment with an anticholinergic or amantadine may be tried.
The following paragraphs describe the commonly prescribed medications :
Has anyone with PD changed medication, when the initial one was not working? 
Stiff person syndrome
ACTIVE-ASSISTED CYCLING improves tremor and bradykinesia in Parkinson's disease.
what do you do when you’re “off”
Muhammad Ali and Young-Onset Idiopathic Parkinson Disease—The Missing Evidence
