Open-Label Clinical Study of Droxidopa in Patients With Neurogenic Orthostatic Hypotension (NOH)

Inclusion Criteria: To be eligible for inclusion, each patient must fulfill the following criteria: * Participated in Droxidopa Protocol 302; * 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: Patients are not eligible for this study if they fulfill one or more of the following criteria: * Currently taking ephedrine or midodrine; * Patients taking ephedrine or midodrine must stop taking these drugs at least 2 days prior to their study entry visit (Visit 1). * Currently taking anti-hypertensive medication; \* 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; * Reproductive potential: * Female subjects should be either post-menopausal (amenorrhea for at least 12 consecutive months), surgically sterile, or women of child-bearing potential (WOCP) who are using or agree to use acceptable methods of contraception. * Acceptable contraceptives include intrauterine devic…