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OpenTrials
Active, Not Recruiting

NCT Number: NCT00262470

Treatment of Orthostatic Intolerance

This trial is designed to study the effects of various mechanistically unique medications in controlling excessive increases in heart rate with standing and in improving the symptoms of orthostatic intolerance in patients with this disorder.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Tachycardia Arrhythmias, Cardiac Autonomic Nervous System Diseases Cardiac Conduction System Disease Cardiovascular Diseases Chronic Orthostatic Intolerance Heart Diseases Nervous System Diseases Orthostatic Intolerance Pathologic Processes Pathological Conditions, Signs and Symptoms Postural Orthostatic Tachycardia Syndrome Primary Dysautonomias Tachycardia, Sinus Tachycardia, Supraventricular

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

Vanderbilt University Autonomic Dysfunction Center

Nashville, Tennessee, 37232-2195, United States

About this study

This trial is designed to study the effects of various mechanistically unique medications in controlling excessive increases in heart rate with standing and in improving the symptoms of orthostatic intolerance in patients with this disorder.

Pilot drug trials are 4h in duration from ~9am -1pm. Different short-acting medications will be used to determine their acute hemodynamic effects in patients with orthostatic intolerance.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Chronic symptoms (> 6 months) with standing upright

Exclusion criteria

  • Obvious cause of hypovolemia or drugs that could worsen tachycardia
  • Chronic severe medical conditions such as cancer or ischemic heart disease

Treatment and study plan

Acetazolamide

Drug

250 mg PO x 1

Other names: Diamox

Atomoxetine

Drug

10-40 mg PO x 1 dose

Other names: Strattera

No drug

Other

No intervention - just monitoring

Clonidine

Drug

Clonidine 0.05-0.3 mg PO x 1 dose

Other names: Catapres

Entacapone

Drug

Entacapone 200-400 mg PO x 1 dose

Other names: Comtan

Entacapone & Propranolol

Drug

Entacapone 200-400 mg PO x 1 dose AND propranolol 20 mg PO x 1 dose

Other names: Comtan, Inderal

Atomoxetine & Propranolol

Drug

Atomoxetine 10-40 mg PO x 1 dose AND propranolol 20 mg PO x 1 dose

Other names: Strattera, Inderal

Indomethacin

Drug

Indomethacin 25-50 mg PO x 1 dose

Other names: Indocin

mecamylamine

Drug

mecamylamine 1.25-5 mg PO x 1 dose

Other names: inversine

Isosorbide Dinitrate

Drug

Isosorbide dinitrate 5-20 mg PO x 1 dose

Other names: Isordil

melatonin

Dietary Supplement

melatonin 3 mg PO x 1 dose

Midodrine

Drug

midodrine 2.5-10 mg PO x 1 dose

Other names: pro-amatine

Modafinil

Drug

modafinil 100-200 mg PO x 1 dose

Other names: provigil

Octreotide

Drug

octreotide 12.5-50 mcg Subcutaneous x 1 dose

Other names: sandostatin

Placebo

Radiation

lactose tablet x 1 pill

Propranolol

Drug

Propranolol 10-80 mg PO x 1-2 dose

Other names: Inderal

Modafinil & Propranolol

Drug

Modafinil 100-200 mg PO x 1 dose AND Propranolol 20 mg PO x 1 dose

Other names: Provigil, Inderal

Sertraline

Drug

sertraline 25-50 mg PO x 1 dose

Other names: Zoloft

IV Saline

Procedure

1 liter IV over 2 hours

Other names: NaCl solution (0.9%)

Drinking Water

Other

16 fluid ounces

Breathing Device

Device

Breathing through a dead space tube

Memantine

Drug

memantine 5-20 mg PO x 1 dose

Other names: Namenda

Abdominal Binder

Device

Using large blood pressure cuffs linked together, they are wrapped around the subjects abdomen and inflated to generate increased pressure to below tolerably threshold.

Primary outcomes

  1. Increase in heart rate with standing

    Time frame: 1-4 hours

Secondary outcomes

  1. Sitting heart rate

    Time frame: 1-4 hours

  2. Standing heart rate

    Time frame: 1-4 hours

  3. Blood pressure

    Time frame: 1-4 hours

  4. Decrease in blood pressure with standing

    Time frame: 1-4 hours

  5. Orthostatic symptoms score

    Time frame: Baseline, 2h, 4h

Sponsors and collaborators

Lead sponsor

Satish R. Raj

Other

Collaborators

  • National Center for Advancing Translational Sciences (NCATS)

Registry information

Important dates

Study start
1997
Primary completion
2029
Study completion
2029
First posted
Dec 6, 2005
Registry last updated
Oct 8, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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