Actively Recruiting
The Effects of Midodrine and Droxidopa on Splanchnic Capacitance in Autonomic Failure Aim 2 of RDCRN Project 2
Led by Vanderbilt University Medical Center · Updated on 2025-10-14
34
Participants Needed
1
Research Sites
13 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying the effects of two medications, midodrine and droxidopa, on blood vessel function in the abdomen of patients who have autonomic failure and experience low blood pressure when standing (orthostatic hypotension). This randomized, double-blind study involves patients with multiple system atrophy, pure autonomic failure, or Parkinson disease. The purpose is to understand how these drugs affect stroke volume during a head-up tilt test. The study enrolls about 34 participants who will be randomly assigned to receive either droxidopa or midodrine in a two-arm parallel design. Each participant will attend two study days spaced two days apart: one day they will receive an active drug dose (droxidopa 300 mg or midodrine 10 mg), and on the other day they will receive placebo. On each day, participants undergo two tilt table tests with measurements taken before and after drug administration, including blood pressure, heart rate, cardiac output, and venous capacitance. Abdominal compression may be applied during the second tilt test to further assess effects. Participants will be involved for about five days including screening and testing. During screening, medical history, physical exams, ECG, laboratory tests, and autonomic testing will be done. Throughout testing days, detailed monitoring and measurements are taken to evaluate drug effects on the cardiovascular system during body position changes. Researchers will assess stroke volume during head-up tilt as the primary outcome. Safety and symptom severity will also be monitored during the study period.
CONDITIONS
Brief Title
Effects of Midodrine and Droxidopa on Splanchnic Capacitance in Autonomic Failure
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Male and female subjects aged 40 to 80 years
- Diagnosis of 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 or greater decrease in systolic blood pressure within 3 minutes of standing with impaired autonomic reflexes
- Ability and willingness to provide informed consent
You will not qualify if you...
- Supine hypertension with systolic blood pressure of 160 mmHg or higher on two separate occasions
- Pregnancy
- Systemic illnesses causing autonomic neuropathy such as diabetes mellitus, amyloidosis, monoclonal gammopathies, and autoimmune neuropathies
- History of aortic aneurysms or thoracic, abdominal, or pelvic surgery within the past 6 months
- Symptomatic abdominal or inguinal hernias
- Severe gastroesophageal reflux
- Recent fractures or fissures of ribs, thoracic or lumbar spine
- Implanted medical devices on the abdominal wall or abdomen interfering with abdominal compression
- Intolerance to increased intraabdominal pressure
- Clinically unstable coronary artery disease or major cardiovascular or neurological events within the past 6 months
- Other clinical, mental, or laboratory abnormalities that would prevent completion of the study protocol
AI-Screening
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Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 2 days
Participants receive single oral doses of either droxidopa or midodrine on separate study days, each followed by placebo dosing, with measurements taken during tilt table tests before and after dosing.
2 study days, two days apart, each including two tilt table tests
Trial Site Locations
Total: 1 location
1
Autonomic Dysfunction Center/ Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Actively Recruiting
Research Team
B
Bonnie K Black, RN
L
Luis E Okamoto, MD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
DOUBLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
2
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