Safety and Efficacy of Droxidopa for Fatigue in Patients With Parkinsonism

Inclusion Criteria: * Age of 50 years or older. * Clinical diagnosis of Parkinsons Disease or Atypical Parkinsonism (including multiple system atrophy (MSA), PSP) * Fluent in English * Reported fatigue and must have a mean VAFS score of 4 or more at baseline * Written informed consent Exclusion Criteria: * Inability to understand or cooperate with study procedures * Alcohol or substance use disorder within the past 12 months (as per Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria) * Women who are pregnant or breastfeeding * Women of childbearing potential (WOCP) as indicated by one of the following: * Sustained supine hypertension greater than or equal to 180 mmHg systolic or 110 mmHg diastolic. Sustained is defined as the average of 3 observations each at least 10 minutes apart with the patient having been supine and at rest for at least 5 minutes prior to each measurement * Untreated closed angle glaucoma * Diagnosis of hypertension that requires treatment with antihypertensive medications * Any significant uncontrolled cardiac arrhythmia * History of myocardial infarction, within the past 2 years * Current unstable angina * Congestive heart failure (NYHA Class 3 or 4) * Diabetic autonomic neuropathy * History of cancer within the past 2 years other than a successfully treated, non-metastatic cutaneous squamous cell or basal cell carcinoma or cervical cancer in situ * Gastrointestinal condition that may affect the absorption of Investigational Medicinal Product (e.g. ulcerative colitis, gastric bypass) * Any major surgical procedure within 30 days prior to the first titration visit. * Currently receiving any investigational drug or have received an investigational drug within 28 days prior to the first titration visit * Any condition or laboratory test result, which in the Investigator's judgment, might result in an increased risk to the patient, or would affect their participation in the study * Dementia or non-treated depression * Subjects who have a mean VAFS score of less than 4 at baseline * Vulnerable populations * Uncontrolled intercurrent illnesses including, but not limited to severe lung disease, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, symptomatic cardiac arrhythmia, and situations that would limit compliance with study requirements will be excluded * Orthostatic hypotension (OH)