A Clinical Study for Patients With Neurogenic Orthostatic Hypotension (NOH) Using Droxidopa

Inclusion Criteria: To be eligible for inclusion, each patient must fulfill the following criteria: * Male or female and aged 18 years or over * Clinical diagnosis of orthostatic hypotension associated with Primary Autonomic Failure (PD, MSA and PAF), Dopamine Beta Hydroxylase Deficiency or Non-Diabetic Autonomic Neuropathies * A documented fall in systolic blood pressure of at least 20 mmHg, or in diastolic blood pressure of at least 10 mmHg, within 3 minutes after standing; * Provide written informed consent to participate in the study and understand that they may withdraw their consent at any time without prejudice to their future medical care. Exclusion Criteria: * Currently taking ephedrine or midodrine * Patients taking ephedrine or midodrine must stop taking these drugs at least 2 days prior to their baseline visit (Visit 2). * The use of short-acting anti-hypertensive medications at bedtime is permitted. * Currently taking tri-cyclic antidepressant medication or other norepinephrine re-uptake inhibitors; * Have changed dose, frequency and or type of prescribed medication, within two weeks of study start (excluding ephedrine and midodrine) * History of more than moderate alcohol consumption * History of known or suspected drug or substance abuse * Women of childbearing potential who are not using a medically accepted contraception * For WOCP a serum beta HCG pregnancy test must be conducted at screening, and a urine pregnancy test must be conducted at baseline and …