This study is examining **ampreloxetine** for treating people with Multiple System Atrophy (**MSA**) who have symptomatic Neurogenic Orthostatic Hypotension (**nOH**). MSA is a condition affecting the nervous system, causing coordination problems (cerebellar subtype) or symptoms like those of Parkinson's disease (Parkinsonian subtype). nOH is a drop in blood pressure when standing, causing dizziness or fainting. The study has four parts: screening, open-label (everyone gets the drug), randomized withdrawal, and long-term treatment.

• The study lasts 20 weeks, with multiple visits required.
• Participants need to be at least 30 years old, diagnosed with MSA, and meet nOH criteria.
• Participants must avoid certain drugs and agree to use birth control if applicable.

People with certain illnesses, recent surgeries, or those taking specific medications cannot join. Participants must not be pregnant, breastfeeding, or have severe heart conditions. This study involves taking ampreloxetine, and participants must agree to follow all study procedures. It's important to consider risks, requirements, and exclusions before joining. Participants should communicate well with the study team and understand the study's expectations.