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Postural Tachycardia SyndromePhase 2NCT00409435

A Study of Pyridostigmine in Postural Tachycardia Syndrome

A Phase 2 study testing pyridostigmine in people with Postural Tachycardia Syndrome, run by Mayo Clinic at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This is a 3-day study comparing pyridostigmine versus placebo in the treatment of postural tachycardia syndrome (POTS). The researchers expect pyridostigmine to improve tachycardia and stabilize blood pressure. Read more about this study

Who is it for?
Ages 15 to 55 years
Conditions the study is for
Postural Tachycardia Syndrome
What is being tested?
pyridostigmine
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
50 participants
Where
1 siteUnited States
Study dates
Oct 2006to Feb 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 15 to 55 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • Diagnosis of postural tachycardia syndrome using the following criteria:
  • Orthostatic heart rate increment greater than or equal to 30 beats per minute (bpm) within 5 minutes of head-up tilt.
  • Symptoms of orthostatic intolerance. These include weakness, lightheadedness, blurred vision, nausea, palpitations, and difficulty with concentration and thinking.
  • Both criteria must be fulfilled.

Who cannot join

  • Pregnant or lactating women
  • Presence of failure of other organ systems or systemic illness that could affect autonomic function or the patient's ability to cooperate with the study
  • Hypothyroidism or hyperthyroidism
  • Clinically significant coronary artery disease
  • Medications that could interfere with autonomic testing
  • Previous treatment with pyridostigmine for POTS. Patients must not have taken pyridostigmine in the past month

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United States1 site, 1 recruiting
  • Mayo Clinic

    Rochester, Minnesota, 55905

    Toni Gehrking, 507-284-0336, adc.research@mayo.edu

    Wolfgang Singer, M.D.

    Recruiting

Other trials in United States

About this study

Official title: Double-Blind, Placebo-Controlled Study of Pyridostigmine in Postural Tachycardia Syndrome

This is a 3-day study comparing pyridostigmine versus placebo in the treatment of postural tachycardia syndrome (POTS). The researchers expect pyridostigmine to improve tachycardia and stabilize blood pressure.

Read the detailed description

The study will be done at the outpatient General Clinical Research Center (GCRC) at Charlton 7 and will involve two visits. Visit 1 will take about 3 hours, and Visit 2 will occur 2 days after Visit 1 and will take about 2 hours.

You will be put in one of two groups by chance (as in the flip of a coin). One group will be taking placebo (an inactive substance), the other group 180 mg pyridostigmine in time release formulation. Both placebo and pyridostigmine will look identical and will be taken as one capsule per day for 3 days. Neither you nor the study doctor will know at the time of treatment whether the treatment being given is active or inactive. However, in case of an emergency, this information will be available.

For each of the two visits, the following tests and procedures will be performed:

  • When you arrive at the GCRC, you will have a general medical and neurological examination and height and weight measurement.
  • Questionnaires. You will be asked to answer a series of questions on your autonomic symptoms (such as rapid heart rate, feeling of tiredness, cold and sweaty hands) at each of your two visits. The questionnaire you will be given during your first visit should take approximately 30 minutes to complete. The questionnaire you will be given during your second visit should take approximately 10 minutes to complete.
  • Autonomic Reflex Screen. An autonomic reflex screen will be done during each visit. This consists of the following:
  • Quantitative sudomotor axon reflex test (QSART): QSART is a routine clinical test that evaluates the response of the sweat gland to a drug, acetylcholine. One capsule is placed on your forearm and three on your leg and foot. The testing is done by passing a small electrical current, for 5 minutes, to activate the nerves that supply the sweat glands. You will feel a slight burning sensation.
  • Cardiovascular recordings: Blood pressure, heart rate, and other cardiovascular measurements will be studied by placing electrodes on the chest and a finger or wrist cuff for continuous blood pressure recordings.
  • Valsalva maneuver: This involves blowing very hard into a bugle (like blowing up a balloon) for 15 seconds.
  • Head-up tilt: Following a period of rest (at least 5 minutes), you will be tilted up to an angle of not more than 80 degrees and recordings will be made for up to 30 minutes. On Visit 1, one hour after you have taken the study medication, this test will be repeated. This test will be done only once on Visit 2.
  • Hormone level measurements: This will be done during each visit. An IV will be inserted into a vein in your arm from which approximately one teaspoon of blood will be drawn while you are lying down and one teaspoon after standing up. This will be repeated only on Visit 1, one hour after the study drug is given. A total of four teaspoons of blood will be drawn on Visit 1 and 2 teaspoons will be drawn on Visit 2.
Being tested
pyridostigmine, Placebo
Keywords
Postural tachycardia syndrome (POTS)
Medical subject headings
Postural Orthostatic Tachycardia Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • pyridostigmineDrug

    one 180 mg capsule per day for 3 days

  • PlaceboDrug

    one capsule per day for 3 days

Study groups in NCT00409435
Study groupRoleWhat they receive
pyridostigmineActive comparatorActive study drug
Receives: Drug: pyridostigmine
PlaceboPlacebo comparatorControl
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in orthostatic symptoms using Composite Autonomic Symptom Scale (COMPASS) change

    Measured: 3 days

Secondary outcomes (2)
  1. Heart rate response to head-up tilt

    Measured: 3 days

  2. Plasma norepinephrine change

    Measured: 3 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Dec 2006 (estimated)
  2. Study startOct 2006
  3. Primary completionFeb 2027 (estimated)
  4. Study completionFeb 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00409435
Sponsor's protocol ID
06-002442
Other IDs
P01NS044233
Status last verified
Mar 2026
First submitted
6 Dec 2006
Last updated
5 Mar 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing pyridostigmine in people with Postural Tachycardia Syndrome, run by Mayo Clinic at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 5 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in orthostatic symptoms using Composite Autonomic Symptom Scale (COMPASS) change (time frame: 3 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Mar 2026.

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