Sustained Effect of Droxidopa in Symptomatic Neurogenic Orthostatic Hypotension

This is a multi-site, placebo-controlled, double-blind, randomized withdrawal, time to intervention study with a duration of up to 36 weeks, consisting of 5 periods: Screening Period: up to 4 weeks duration; Open-Label Titration Period (Titration Period): up to 4 weeks duration; Open-Label Treatment Period (Open-Label Period): 12 weeks duration; Double-Blind Treatment Period (Double-Blind Period): 12 weeks duration; Safety Follow-Up Period: 4 weeks duration