Autonomic Determinants of POTS - Pilot 2
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ClinicalTrials.gov Identifier: NCT04140721 |
Recruitment Status :
Not yet recruiting
First Posted : October 28, 2019
Last Update Posted : December 9, 2020
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Postural tachycardia syndrome (POTS) is a relatively common condition affecting mostly otherwise healthy young women. These patients have high heart rate and disabling symptoms during standing. Quality of life may be poor. The sympathetic nerves in the autonomic nervous system help to maintain normal blood pressures and heart rates during activities of daily life.
The purpose of this study is to determine the importance of sympathetic activation as a cause of orthostatic symptoms. The investigators will assess the effects of a blood pressure medication (Moxonidine) on the symptoms during standing. Moxonidine lowers sympathetic activity. The investigators believe patients with high resting sympathetic activity might benefit from Moxonidine. It might reduce high heart rate and improve symptoms during standing. This study should help clinicians and the growing population of patients with POTS gain a better understanding of this disorder and find more personalized treatment.
Condition or disease | Intervention/treatment | Phase |
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Postural Tachycardia Syndrome | Drug: Placebo oral tablet Drug: Moxonidine Pill | Early Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 48 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Intervention Model Description: | randomized, double blind, crossover design |
Masking: | Double (Participant, Investigator) |
Masking Description: | Vanderbilt's Investigational Pharmacy will randomly assign participants to the moxonidine/placebo or placebo/moxonidine arm of the study. They will also provide the active drug and matching placebo. The medication distribution list will be kept by a dedicated person not involved in the study. |
Primary Purpose: | Other |
Official Title: | Autonomic Determinants of Postural Tachycardia Syndrome (Chronic Pilot Study 2) |
Estimated Study Start Date : | February 1, 2021 |
Estimated Primary Completion Date : | January 1, 2025 |
Estimated Study Completion Date : | December 31, 2025 |
Arm | Intervention/treatment |
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Experimental: Moxonidine then Placebo
After 5 days of screening/baseline evaluations, patients will be discharged home on moxonidine 0.2-0.4 mg/day PO. On days 29, 30 and 31, the patients will be re-admitted for study testing while on moxonidine. At completion of this testing, patients will start taking matching placebo once daily PO to be continued at home. On days 58, 59 and 60, the patients will be re-admitted for study testing while on placebo.
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Drug: Placebo oral tablet
Placebo pill identical to moxonidine administered for 4 weeks
Other Name: inactive pill Drug: Moxonidine Pill Moxonidine pill administered for 4 weeks
Other Name: Physiotens |
Experimental: Placebo then Moxonidine
After 5 days of screening/baseline evaluations, patients will be discharged home on placebo identical to moxonidine once daily PO. On days 29, 30 and 31, the patients will be re-admitted for study testing while on placebo. At completion of this testing, patients will start taking moxonidine 0.2-0.4 mg/day PO to be continued at home. On days 58, 59 and 60, the patients will be re-admitted for study testing while on moxonidine.
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Drug: Placebo oral tablet
Placebo pill identical to moxonidine administered for 4 weeks
Other Name: inactive pill Drug: Moxonidine Pill Moxonidine pill administered for 4 weeks
Other Name: Physiotens |
- Change in Orthostatic Symptom Burden [delta (delta VOSS)] [ Time Frame: after 30 min supine to after 15 min of 60 degrees upright tilt (delta VOSS), 2-3 hours after a dose of the treatment assigned for the previous 4 weeks. ]VOSS is a validated questionnaire that consists of 9 items: mental clouding, blurred vision, shortness of breath, rapid heartbeat, tremulousness, chest discomfort, headache, lightheadedness, and nausea. Each item is scored on a 0 to 10 scale (with 0 reflecting absence of symptoms), and the change of the total scores (range: 0-90) from supine to upright postures (delta VOSS) will be used as a measure of orthostatic symptom burden. The primary outcome measure will be the difference in orthostatic symptom burden [delta (delta VOSS)] following 4 weeks of placebo vs. moxonidine treatment.
- Change in Orthostatic Change in Heart Rate [delta (delta HR)] [ Time Frame: after 30 min supine to after 15 min of 60 degrees upright tilt (delta HR), 2-3 hours after a dose of the treatment assigned for the previous 4 weeks. ]Difference in heart rate change from supine to upright postures (delta HR) following 4 weeks of placebo vs. moxonidine treatment [delta (delta HR)].

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Ages Eligible for Study: | 18 Years to 55 Years (Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
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meets criteria for postural tachycardia syndrome (POTS)
- a heart rate increase of ≥30 beats/min within 10 minutes of upright posture;
- lack of orthostatic hypotension (blood pressure fall ≥ 20/10 mmHg within 3 minutes of standing); and
- chronic symptoms during upright posture over at least 6 months, in the absence of any other acute cause.
- in the follicular phase of the menstrual cycle (days 5-13 of a 28-day cycle)
- POTS with primary central sympathetic activation (psPOTS) as defined as having resting MSNA ≥ 25 bursts/min
- able and willing to provide informed consent.
Exclusion Criteria:
- pregnancy,
- smoker,
- BMI>30 kg/m2,
- deconditioned status (if available VO2max<80% of predicted)
- unable to withdraw from medications known to affect autonomic function, blood pressure or blood volume
- systemic illnesses known to produce autonomic neuropathy, including but not limited to diabetes mellitus, amyloidosis, monoclonal gammopathies, and autoimmune neuropathies.
- arteriosclerotic disease of carotid artery. History of neck surgery.
- conditions associated with inflammatory processes, such as coronary artery disease, hypertension, smoking, hypercholesterolemia (or on statin therapy), rheumatoid arthritis, diabetes,
- treatment with oral corticosteroids, current infections (e.g., urinary tract infection), or use of non-steroidal anti-inflammatory drugs.
- 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.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04140721
Contact: Emily C Smith, RN | 615 875-1516 ext 6153436833 | autonomics@vumc.org |
Principal Investigator: | André Diedrich, MD | Vanderbilt University Medical Center |
Responsible Party: | Andre' Diedrich, Research Professor of Medicine, Vanderbilt University Medical Center |
ClinicalTrials.gov Identifier: | NCT04140721 |
Other Study ID Numbers: |
VANDERBILT_IRB_191749 R01HL142583 ( U.S. NIH Grant/Contract ) |
First Posted: | October 28, 2019 Key Record Dates |
Last Update Posted: | December 9, 2020 |
Last Verified: | December 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
postural tachycardia syndrome hyperadrenergic moxonidine |
sympatholytic orthostatic symptoms POTS |
Postural Orthostatic Tachycardia Syndrome Tachycardia Syndrome Disease Pathologic Processes Arrhythmias, Cardiac Heart Diseases Cardiovascular Diseases |
Cardiac Conduction System Disease Orthostatic Intolerance Primary Dysautonomias Autonomic Nervous System Diseases Nervous System Diseases Moxonidine Antihypertensive Agents |