Clinical Research Directory

Inclusion Criteria: * 50-80 years old at the time of enrollment with a diagnosis of idiopathic PD per the Movement Disorder Society's Diagnostic Criteria. * Subjects must NOT be taking more than 2 dopaminergic treatments for their PD at the time of enrollment. * Practically defined OFF Hoehn and Yahr score of 0-2. * Diagnosis of PD made within the preceding 3 years. Exclusion Criteria: * • Orthostatic hypotension at screening is defined as decrease in BP \> 20 mmHg systolic or \> 10 mmHg diastolic and HR increase \<20 bpm on transition from supine to sitting or standing. * Known allergy or previous adverse reaction to TZ or related compounds. * Current use of TZ or concurrent use of DZ, AZ, prazosin, or tamsulosin. * History of hepatic dysfunction. * History of clinically relevant anemia. * Secondary parkinsonism, drug-induced parkinsonism, Parkinson's-plus syndromes, or non-idiopathic PD. * PD including use of more than two dopaminergic medications at screening. * History of deep brain stimulation. * Dementia per Movement Disorder Society Level 1 criteria. * Traumatic brain injury or post-traumatic stress disorder. * Presence of a confounding acute or unstable medical, psychiatric, or orthopedic condition. * Unstable use of medications that modulate the central nervous system. * Uncontrolled major depression or bipolar affective disorder, or other mental health disorders that are, in the opinion of the site investigator, sufficiently severe to increase risk of experiencing an Adverse Drug Reaction (ADR). * Current suicidal ideation as measured by questions 4 or 5 of the Columbia-Suicide Severity Rating Scale. * Participants with insufficient decisional capacity to provide written informed consent determined by the site investigator. * Unstable use of antihypertensive medications.