Phase 3
Completed N=28
Peripheral Dopamine in Postural Tachycardia Syndrome
Postural Tachycardia Syndrome · Orthostatic Intolerance
Source: ClinicalTrials.gov NCT00685919 ↗
Enrolled (actual)
28
Serious AEs
0.0%
Results posted
Sep 2021
Primary outcomePrimary: 24 Hour Urinary Sodium Excretion During Treatment Normalized to Creatinine — 140; 132; 137; 154 Milliequivalents per gram (mEq/g)
◆ Published Evidence
No publication linked
No peer-reviewed publication reporting this trial's results has been linked yet. This can indicate results are unpublished — a known publication-bias signal. We re-check periodically.
Summary
The purpose of the proposed research is to determine how changes in kidney dopamine (DA) activity influence urinary sodium excretion. We will decrease DA activity in the kidney by inhibiting DA synthesis via carbidopa administration. We want to compare findings in normal volunteers and in patients with postural tachycardia syndrome (POTS). We will test the null hypothesis (Ho) that the effects of oral carbidopa administration on urinary sodium excretion will not differ between patients with POTS and healthy volunteers.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY 24 Hour Urinary Sodium Excretion During Treatment Normalized to Creatinine |
140; 132; 137; 154 | — |
| SECONDARY Systolic Blood Pressure Measured at 8 Hours After the Last Dose of Placebo or Carbidopa |
103; 101; 102; 101 | — |
| SECONDARY Plasma Catecholamines (Norepinephrine) After the Last Dose of Placebo or Carbidopa |
150; 181; 278; 245 | — |
| SECONDARY Plasma Catecholamines (DOPA) After the Last Dose of Placebo or Carbidopa |
1813; 20297; 2104; 25680 | — |
| SECONDARY 24 Hour Urinary Catecholamine (DOPA) Excretion During Treatment Normalized to Creatinine |
0.024; 0.283; 0.026; 0.385 | — |
| SECONDARY 24 Hour Urinary Catecholamine (Dopamine) Excretion During Treatment Normalized to Creatinine |
0.208; 0.035; 0.24; 0.038 | — |
| SECONDARY Supine Plasma Renin Activity 2 Hours After the Last Dose of Placebo or Carbidopa |
1.153; 1.033; 1.544; 1.878 | — |
| SECONDARY Plasma Sodium After the Last Dose of Placebo or Carbidopa |
138; 138; 139; 138 | — |
Eligibility Criteria
Inclusion Criteria
- Patients diagnosed with POTS by the Vanderbilt Autonomic Dysfunction Center based on the following stringent criteria: 1) history of daily orthostatic symptoms for at least 6 months; 2) increase in heart rate (HR) of at least 30 bpm with standing or a standing HR of at least 120 bpm; 3) absence of orthostatic hypotension (defined as a fall in blood pressure (BP)>20/10 mm Hg); and 4) absence of conditions, such as dehydration, substantial weight loss, or systemic illnesses, that could provoke orthostatic intolerance
- Upright plasma NE at least 600 pg/mL in patients
- Non-smoking
- Free of medications with the potential to influence BP
- Able and willing to provide informed consent -
Exclusion Criteria
- Overt cause for postural tachycardia (such as acute dehydration)
- Significant cardiovascular, pulmonary, hepatic, or hematological disease by history or screening results
- Positive urine b-hcg pregnancy test
- Evidence of cardiac structural disease (by clinical examination or prior echocardiogram)
- Hypertension defined as a BP>145/95 (off medications) or need for antihypertensive medications
- Evidence of significant conduction system delay (QRS duration >120 ms) on electrocardiogram
- Inability to give, or withdraw, informed consent
Data sourced from ClinicalTrials.gov (NCT00685919). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.