Additional Study Information: You may be eligible to take part in the study because you have a diagnosis of Multiple System Atrophy (MSA) with the symptoms of neurogenic Orthostatic Hypotension (nOH). MSA is a rare disorder in adults that progresses rapidly and ultimately is a fatal neurodegenerative disease. It is characterized by autonomic failure affecting blood pressure regulation, movement and balance. Autonomic failure occurs when the autonomic nervous system, which controls functions responsible for well-being and maintaining balance, does not regulate properly. The main purpose of this study is to look at Ampreloxetine (referred to as the study drug) and assess its efficacy in treating nOH symptoms in people with MSA.