Please note that the continuation study can be found at http://clinicaltrials.gov/show/NCT00633880.

RATIONALE: Neurogenic hypotension is a fall in blood pressure that occurs when one moves from a lying down to a standing position or after eating a meal. It causes one to feel dizzy, light headed, and weak. Neurogenic hypotension is caused by a problem in the part of the nervous system that controls such functions as heart rate and blood pressure. Droxidopa, a drug that may increase blood pressure, may be an effective treatment for neurogenic hypotension.

PURPOSE: Clinical trial to study the effectiveness of droxidopa in treating patients who have neurogenic hypotension.

PROTOCOL OUTLINE:

Patients receive escalating doses of droxidopa or placebo for 7-14 days. Patients undergo blood pressure measurements hourly in both supine and standing positions.

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

• Orthostatic hypotension due to autonomic nervous system failure Fall in systolic blood pressure (supine to standing) of at least 20 mm Hg and diastolic blood pressure of at least 15 mm Hg AND Symptoms of hypotension such as dizziness, light-headedness, unsteadiness, dimming or blurred vision
• History of syncope or near-syncope

--Prior/Concurrent Therapy--

• Endocrine therapy: No concurrent adrenergics Concurrent fludrocortisone allowed
• Other: Concurrent indomethacin, support garments, and high salt diets allowed