Safety and Benefit Study of Droxidopa to Treat Patients With Intradialytic Hypotension

Inclusion Criteria: 1. Male or female and aged 18 years or over; 2. Clinical diagnosis of ESRD; 3. Demonstrated requirement to undergo maintenance HD 3 times per week for sessions at least 3 hours in duration; 4. Medical history consistent with IDH existing for at least 1 month; 5. Observed symptomatic intradialytic hypotension in 3 of 6 HD sessions during screening, as defined by as a decrease in systolic blood pressure by ≥20 mm Hg or a decrease in MAP by 10 mm Hg associated with symptoms that include: abdominal discomfort; yawning; sighing; nausea; vomiting; muscle cramps; restlessness; dizziness or fainting; and anxiety (definition according to: National Kidney Foundation 2007) ; 6. 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: 1. Currently taking ephedrine or midodrine; * Patients taking ephedrine or midodrine may enroll after a minimum 7 day washout period 2. Taking anti-hypertensive medication on the day of dialysis; 3. Currently taking selective norepinephrine re-uptake inhibitors; 4. Current known or suspected drug or substance abuse; 5. Women of childbearing potential who are not using a medically accepted contraception; Subject Restrictions: * 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 devices (IUDs), hormonal contraceptives (oral, depot, patch or injectable) and double barrier methods such as condoms or diaphragms with spermicidal gel or foam. * For WOCP a urine/serum beta HCG pregnancy test must be conducted at screening and study termination, and a urine/serum pregnancy test must be conducted at baseline; the results must be negative at screening and at baseline. WOCP must be advised to use acceptable contraceptives throughout the study period and for 30 days after the last dose of investigational product. If hormonal contraceptives are used they should be taken according to the package insert. WOCP who are not currently sexually active must agree to use acceptable contraception, as defined above, if they decide to become sexually active during the period of the study and for 30 days after the last dose of investigational product. 6. Sexually active males whose partner is a WOCP must agree to use condoms for the duration of the study and for 30 days after the last dose; 7. Women who are pregnant or breast feeding; 8. Known or suspected hypersensitivity to the study medication or any of its ingredients; 9. Have active atrial fibrillation (within the last 6 months) or, in the investigator's opinion, have any other significant cardiac arrhythmia; 10. Any other significant systemic, hepatic or cardiac illness; 11. Have a history of closed angle glaucoma; 12. Have a known or suspected malignancy (other than basal cell carcinoma); 13. Patients with known gastrointestinal illness or other gastrointestinal disorder that may, in the investigator's opinion, affect the absorption of study drug; 14. In the investigator's opinion, have clinically significant abnormalities on clinical examination or laboratory testing; 15. In the investigator's opinion, are unable to adequately cooperate because of individual or family situation; 16. In the investigator's opinion, are suffering from a mental disorder that interferes with the diagnosis and/or with the conduct of the study, e.g. schizophrenia, major depression, dementia; 17. Are not able or willing to comply with the study requirements for the duration of the study; 18. Have participated in another clinical trial with an investigational agent (including named patient or compassionate use protocol) within 30 days before the start of the study; 19. Previous enrollment in the study.