Study to Assess Droxidopa in the Treatment of Freezing Of Gait Symptoms in Patients With Parkinson's Disease

Exclusion Criteria

• •Taking direct acting vasoconstricting agent (i.e. ephedrine or midodrine). Patients taking vasoconstrictor agents such as ephedrine or midodrine must stop taking these drugs at least 2 days or 5 half-lives (whichever is longer) prior to their baseline visit;
• •Taking more than one anti-hypertensive medication for the treatment of high blood pressure. Short acting anti-hypertensive medication taken at night to prevent supine hypertension will be allowed.
• •Have changed dose or frequency of Parkinson's medication within 2 weeks of baseline
• •Known or suspected alcohol or substance abuse within 1 year
• •Sustained hypertension (BP greater than 140/90 mmHg in the sitting position)
• •Symptomatic coronary artery disease, severe congestive heart failure
• •Women who are pregnant, lactating, or plan to become pregnant during the course of this study;
• •Women of child bearing potential (WOCP) who are not using two methods of contraception (at least one barrier: i.e. condom) with their partner.
• •Male patients who are sexually active with a woman of child bearing potential (WOCP) and not using two methods of contraception (at least one barrier: i.e. condom)
• •Untreated closed angle glaucoma, or treated closed angle glaucoma that in the opinion of an ophthalmologist would cause increased risk to the patient;
• •Active (last 6 months) atrial fibrillation or, in the investigator's opinion, any other significant cardiac arrhythmia that should preclude the patient from this trial;
• •History of myocardial infarction or unstable angina
• •Diabetes insipidus, insulin dependent diabetes mellitus, or diabetic neuropathy;
• •In the investigator's opinion, any other significant systemic illness;
• •Known or suspected malignancy (other than basal cell carcinoma);
• •Known gastrointestinal illness or other gastrointestinal disorder that may, in the investigator's opinion, affect the absorption of study drug;
• •Any major surgical procedure within 30 days of the baseline visit;
• •Currently receiving any investigational drug or have received an investigational drug within 30 days of the baseline visit;
• •In the investigator's opinion, clinically significant abnormalities on clinical examination or laboratory testing that should preclude the patient from this trial;
• •Patient has only lower body Parkinson's Disease
• •In the investigators opinion, freezing of gait is attributable to previous stroke