Fainting, Postural Tachycardia Syndrome (POTS), Vasovagal Syncope (VVS)
Conditions
Keywords
Postural Tachycardia Syndrome (POTS), Vasovagal Syncope (VVS), Fainting, Orthostatic Intolerance, Droxidopa, Northera
Brief summary
Vasovagal syncope (VVS, simple faint) is the most common cause of transient loss of consciousness and represents the acute episodic form of orthostatic intolerance (OI). Postural tachycardia syndrome (POTS) is the common chronic form of OI. Both are defined by debilitating symptoms and signs while upright relieved by recumbency. Northera should therefore improve both sympathetic splanchnic arterial vasoconstriction and sympathetic splanchnic venoconstriction in POTS and VVS, and may represent an ideal drug to improve the orthostatic response in POTS and VVS.
Detailed description
Vasovagal syncope (VVS, simple faint) is the most common cause of transient loss of consciousness and represents the acute episodic form of orthostatic intolerance (OI). Postural tachycardia syndrome (POTS) is the common chronic form of OI. Both are defined by debilitating symptoms and signs while upright relieved by recumbency. Pathophysiological mechanisms have remained elusive. Most POTS patients and all VVS patients have normal supine resting hemodynamics but excessively redistribute blood flow and blood volume from the central pool to the splanchnic vasculature because of defective splanchnic arterial vasoconstriction and venoconstriction. While peripheral and splanchnic arterial vasoconstriction depend primarily on post-junctional alpha-1 adrenergic receptors, splanchnic venoconstriction also depends on post-junctional alpha-2 adrenergic receptors. Consequently, selective alpha-1 agonists such as midodrine may not produce sufficient splanchnic venoconstriction to compensate for splanchnic pooling in POTS and VVS. Such alpha adrenergic subtype restrictions do not apply to Northera (droxidopa) because it is a norepinephrine (NE) prodrug and therefore increases the amount of synaptic NE that can then bind to both alpha-2 and alpha-1 receptors. Northera should therefore improve both sympathetic splanchnic arterial vasoconstriction and sympathetic splanchnic venoconstriction in POTS and VVS, and may represent an ideal drug to improve the orthostatic response in POTS and VVS. We will test the hypothesis that Northera, in appropriate dose, improves the splanchnic adrenergic deficits that initiate POTS and postural VVS and in sufficient daily dose improves quality of life in these patients. To accomplish this, the investigator will recruit 10 POTS patients aged 18-30 years, 10 similarly aged patients with 2 or more episodes of VVS in the past year (thus defining recurrent VVS) and 10 age and gender matched healthy volunteer control subjects with the following specific aims:
Interventions
DRUGNorthera (Droxidopa)
Study #1 -Supine monitoring is performed for 30 minutes before administration of a single 600mg oral dose of Northera or placebo assigned randomly, After 2 hours supine a 70 degree upright tilt will performed for 10 minutes. On another day, subjects previously given Northera will receive placebo and vice versa and studies repeated.
DRUGPlacebo
Study #1 -Supine monitoring is performed for 30 minutes before administration of a single 600mg oral dose of Northera or placebo assigned randomly, After 2 hours supine a 70 degree upright tilt will performed for 10 minutes. On another day, subjects previously given Northera will receive placebo and vice versa and studies repeated.
Sponsors
Lundbeck LLC
New York Medical College
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Both male and female participants are being studied * Ages 18-30 years old * POTS cases will be referred for day-to-day Orthostatic Intolerance (OI) with ≥3 symptoms for \>6 months. * POTS will be confirmed by medical history indicating chronic OI, and by a prior 700 tilt table test or standing test showing excessive tachycardia and symptoms OI in the absence of hypotension. * VVS (fainting) subjects will have at least 2 episodes of postural VVS during the past calendar year. * Healthy volunteers will be included for Study #1
Exclusion criteria
* Only those free from all systemic illnesses will be eligible to participate. This excludes patients with illnesses associated with autonomic dysfunction such as diabetes, renal disease, congestive heart failure, systemic hypertension, acute and chronic inflammatory diseases, neoplasm, immune mediated disease, trauma, obesity, cancer, supine or upright hypertension, and peripheral vascular disease. * No subjects will be taking neurally active, or vasoactive drugs. Prior medication will be stopped for at least 2 weeks.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Study #1 and Study #2 - Splanchnic and lower extremity pooling (physiological parameter) | 2 weeks | Splanchnic and lower extremity pooling will be measured before, during, and after upright tilt. The investigators will use both venous occlusion plethysmography and impedance plethysmography. Venous occlusion plethysmography are made in ml/min by rapidly inflating cuffs to a pressure of 45mmHg and then computing the slope of the time dependent increase in cross limb section. During impedance plethysmography, a Tetrapolar High Resolution Impedance monitor 4-channel digital IPG is used to detect changes in regional blood volume and blood flow in ml/min |
| Study #2 -Quality of Life measured by self reporting questionnaire (RAND-36) | 6 weeks | The investigators will test whether chronic administration of Northera (Droxidopa) in escalating dose improves quality of life. Quality of life will be measured by the RAND-36 questionnaire. The RAND-36 is a set of generic, coherent, and easily administered quality-of-life measures. These measures rely upon patient self-reporting. The RAND 36-Item Health Survey (Version 1.0) taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. It also includes a single item that provides an indication of perceived change in health. (2-4) |
| Study #2 -Quality of Life measured by self reporting questionnaire (COMPASS 31) | 6 weeks | The investigators will test whether chronic administration of Northera (Droxidopa) in escalating dose improves quality of life. Quality of life will be measured by the RAND-36 questionnaire (as shown in the above primary outcome) as well as the COMPASS 31 questionnaire. The COMPASS 31 was developed as a self-assessment instrument of autonomic symptoms and function that is up-to-date, broadly applicable, easy to administer in a short amount of time, and based on a scientific approach. It was designed to provide a global autonomic severity score and domain scores that are both clinically and scientifically meaningful. COMPASS 31 is based on the well-established ASP \[Autonomic Symptom Profile\], a comprehensive questionnaire assessing autonomic symptoms across multiple domains. (1) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Study #1 and Study #2 -Blood pressure (BP) | 2 weeks | During laboratory testing, blood pressure will be continuously monitored in mmHg |
| Study #1 and Study #2 -Heart rate (HR) | 2 weeks | During laboratory testing, heart rate will be continuously monitored in beats/minute. |
Countries
United States
Outcome results
None listed