Effects of Midodrine and Droxidopa on Splanchnic Capacitance in Autonomic Failure
Autonomic Failure, Pure Autonomic Failure, Multiple System Atrophy
About this trial
This is an interventional basic science trial for Autonomic Failure focused on measuring midodrine, droxidopa, splanchnic circulation
Eligibility Criteria
Inclusion Criteria:
- Male and female subjects, age 40-80 years with possible or probable Multiple System Atrophy, Pure Autonomic Failure, or Parkinson disease, as defined by Consensus Criteria.
- Neurogenic orthostatic hypotension defined as a ≥30-mmHg decrease in systolic blood pressure within 3 minutes of standing associated with impaired autonomic reflexes determined by autonomic testing in the absence of other identifiable causes.
- Subjects able and willing to provide informed consent.
Exclusion Criteria:
- Supine hypertension, defined as systolic blood pressure of ≥ 160 mmHg measured on two separate occasions.
- Pregnancy.
- Systemic illnesses known to produce autonomic neuropathy, including but not limited to diabetes mellitus, amyloidosis, monoclonal gammopathies, and autoimmune neuropathies.
- History of known aortic aneurisms, thoracic, abdominal or pelvic surgery in the past 6 months.
- Symptomatic abdominal or inguinal hernias.
- Severe gastroesophageal reflux.
- Recent fractures or fissures of ribs, thoracic or lumbar spine.
- Medical devices implanted on the abdominal wall or abdomen that would interfere with the abdominal compression.
- Intolerance to any increase in intraabdominal pressure.
- Clinically unstable coronary artery disease or major cardiovascular or neurological event in the past 6 months, and other factors which in the investigator's opinion would prevent the subject from completing the protocol including clinically significant abnormalities in clinical, mental or laboratory testing.
Sites / Locations
- Autonomic Dysfunction Center/ Vanderbilt University Medical CenterRecruiting
Arms of the Study
Arm 1
Arm 2
Experimental
Experimental
Droxidopa and Placebo
Midodrine and Placebo
Patients will be studied on two separate days, two days apart: one day with the active drug and one day with placebo. The order of the study days will be randomized. On each study day, patients will receive a single oral dose of either droxidopa 300 mg or placebo after the first tilt table test, followed two hours later by a single oral dose of placebo.
Patients will be studied on two separate days, two days apart: one day with the active drug and one day with placebo. The order of the study days will be randomized. On each study day, patients will receive a single oral dose of placebo after the first tilt table test, followed two hours later by a single oral dose of either midodrine 10 mg or placebo.