Carbidopa for the Treatment of Excessive Blood Pressure Variability

Inclusion Criteria: * Male or female patients with familial dysautonomia (FD) age 10 or older * Unstable blood pressure, defined as: * Systolic BP standard deviation \>15 mmHg * Or coefficient of variation \>15% * Or documented episodic hypertensive peaks (\>140mmHg) * Confirmed diagnosis of FD (genetic testing) * Providing written informed consent (or ascent) to participate in the trial * Ability to comply with the requirements of the study procedures. Exclusion Criteria: * Patients taking monoamine oxidase (MAO)-inhibitors * Patients taking: metoclopramide, domperidone, risperidone or other dopamine blockers * Patients taking tricyclic antidepressants * Patients taking neuroleptic drugs (haloperidol and chlorpromazine) * Patients with a known hypersensitivity to any component of this drug. * Patients with atrial fibrillation, angina or significant ECG abnormality * Patients with significant pulmonary, cardiac, liver, renal (creatinine \>2.0 mg/ml) * Patients who have a significant abnormality on clinical examination that may, in the investigator's opinion might jeopardize their healthy participating in this trial. * Women who are pregnant or lactating.