Carbidopa for the Treatment of Nausea and Vomiting in Familial Dysautonomia
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ClinicalTrials.gov Identifier: NCT01212484 |
Recruitment Status :
Completed
First Posted : September 30, 2010
Results First Posted : March 28, 2016
Last Update Posted : March 28, 2016
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This is a pilot clinical trial of carbidopa to treat disabling attacks of nausea and vomiting in patients with familial dysautonomia (FD, also known as Riley Day syndrome or hereditary sensory and autonomic neuropathy type III). FD is a rare autosomal recessive disease in which the growth and development of selective nerves is impaired. Patients with FD suffer recurrent uncontrollable nausea and vomiting crises accompanied by skin flushing, tachycardia and arterial hypertension. Current treatments of nausea are ineffective or have intolerable side sides. Our long-term goal is to treat nausea effectively and without side effects, a therapeutic intervention that would markedly improve the quality of life of patients with FD.
The investigators have recently found that resting plasma dopamine levels are high in patients with FD and increase up to 40-fold during nausea and vomiting attacks. This led us to postulate that stimulation of dopamine receptors in the chemoreceptor trigger zone of the brainstem is the likely mechanism of vomiting.
Carbidopa is a reversible competitive inhibitor of aromatic L-amino acid decarboxylase (also known as dopa-decarboxylase) that cannot cross the blood brain barrier. It has been used successfully for many years to block the extracerebral synthesis of dopamine and avoid nausea and vomiting in patients with Parkinson's disease taking levodopa. The investigators reasoned that carbidopa could have a similar antiemetic effect in patients with FD.
The investigators propose to conduct a pilot trial to assess the safety, tolerability and efficacy of carbidopa for the treatment of nausea in patients with FD. The pilot trial will recruit 25 patients with FD who complain of severe nausea that affects their quality of life. The trial will be divided into two consecutive, but independent parts. Part 1, will address the safety and tolerability of carbidopa in patients with FD using an open-label dose titration phase followed by 4-weeks of open-label treatment. Part 2, will address the efficacy of carbidopa for the treatment of nausea in patients with FD using a randomized, placebo controlled, double blind, 4-week cross over design.
The investigators hope to demonstrate that carbidopa is a safe, well-tolerated drug that blocks the peripheral formation of dopamine and thus prevents dopamine-induced nausea and vomiting attacks in patients with FD.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Familial Dysautonomia | Drug: Carbidopa Drug: Placebo | Phase 3 |
Patients with familial dysautonomia (FD), also called Riley Day syndrome or hereditary sensory and autonomic neuropathy type III, suffer recurrent attacks of uncontrollable nausea and vomiting that can last several hours or days and are severely disabling. Hypertension, tachycardia and skin blotching frequently accompany these attacks. Our long-term objective is to develop an effective treatment for nausea and vomiting in patients with FD.
In preliminary studies we found that plasma levels of dopamine were very high during attacks. Stimulation of dopamine receptors in the chemoreceptor trigger zone in the brainstem is a well-known cause of nausea and vomiting. The investigators postulate that acute increases in circulating dopamine levels are the cause of paroxysmal nausea and vomiting in FD.
Dopamine is synthesized by decarboxylation of the aminoacid L-dihydroxyphenylserine (L-DOPA) by the enzyme aromatic L-aminoacid decarboxylase, also known as DOPA decarboxylase. Patients with Parkinson's disease suffer nausea and vomiting when they receive treatment with L-DOPA. However, when L-DOPA is administered together with carbidopa, a reversible competitive inhibitor of DOPA decarboxylase that does not cross the blood brain barrier, nausea and vomiting are prevented. The investigators hypothesize that by blocking the conversion of DOPA to dopamine and thus preventing its increase in plasma, treatment with carbidopa will decrease nausea and vomiting in patients with FD.
Although carbidopa has been used for many years in patients with Parkinson's disease, it has never been used in patients with FD. The first specific aim of this proposal is to assess the safety and tolerability of carbidopa in patients with FD.
The second specific aim of this proposal is to determine whether blocking the peripheral synthesis of dopamine with carbidopa will improve recurrent nausea in patients with FD.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 12 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Treatment |
Official Title: | Carbidopa for the Treatment of Nausea and Vomiting in Familial Dysautonomia |
Study Start Date : | December 2009 |
Actual Primary Completion Date : | February 2012 |
Actual Study Completion Date : | October 2012 |

Arm | Intervention/treatment |
---|---|
Experimental: Placebo (first), Carbidopa (second)
Crossover design Placebo first followed by carbidopa
|
Drug: Carbidopa
The trial will be divided into two consecutive, but independent parts. Phase 1, will address the safety and tolerability of carbidopa in patients with FD using an open-label dose titration phase followed by 4-weeks of open-label treatment. Phase 2, will address the efficacy of carbidopa for the treatment of nausea in patients with FD using a randomized, placebo controlled, double blind, 4-week cross over design.
Other Name: Lodosyn Drug: Placebo The trial will be divided into two consecutive, but independent parts. Phase 1, will address the safety and tolerability of carbidopa in patients with FD using an open-label dose titration phase followed by 4-weeks of open-label treatment. Phase 2, will address the efficacy of carbidopa for the treatment of nausea in patients with FD using a randomized, placebo controlled, double blind, 4-week cross over design. |
Experimental: Carbidopa (first), Placebo (second)
Crossover design carbidopa first followed by placebo
|
Drug: Carbidopa
The trial will be divided into two consecutive, but independent parts. Phase 1, will address the safety and tolerability of carbidopa in patients with FD using an open-label dose titration phase followed by 4-weeks of open-label treatment. Phase 2, will address the efficacy of carbidopa for the treatment of nausea in patients with FD using a randomized, placebo controlled, double blind, 4-week cross over design.
Other Name: Lodosyn Drug: Placebo The trial will be divided into two consecutive, but independent parts. Phase 1, will address the safety and tolerability of carbidopa in patients with FD using an open-label dose titration phase followed by 4-weeks of open-label treatment. Phase 2, will address the efficacy of carbidopa for the treatment of nausea in patients with FD using a randomized, placebo controlled, double blind, 4-week cross over design. |
- Composite Daily Score [ Time Frame: 4 weeks ]Daily scores were reported on a modified version of the Rhodes Index of Nausea, Vomiting and Retching, which included all 5 items relating to nausea and retching. Items addressing vomiting/throwing up were omitted, as all participants had antireflux surgery that prevented vomiting (Nissen fundoplication). Retching distress, nausea distress, number of nausea episodes per day, number of retching episodes per day, and the amount of time spent feeling nauseous were graded on a 5-point scale. Scores range from 0 (no nausea/distress) to 20 (most nausea/distress).
- 24 Hour Dopamine Levels [ Time Frame: 4 weeks ]Assay of 24 hour dopamine level excretion in urine
- Number of Episodes of Daily Nausea [ Time Frame: 4 weeks ]

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Ages Eligible for Study: | 12 Years and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Male of female patients aged 12 and older
- Confirmed diagnosis of familial dysautonomia by genetic testing.
- Symptoms of severe nausea
- Written informed consent or ascent to participate in the pilot trial and understanding that they can withdraw consent at anytime without affecting their future care.
- Ability to comply with the requirements of the study procedures, including taking blood pressure measurements at home.
Exclusion Criteria:
- Patients taking metroclopromide, domperidone, risperidone or other dopamine blockers
- Patients taking MAO-inhibitors
- 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 an electrocardiogram documenting significant abnormality that may jeopardize the patient's health.
- Patients with significant pulmonary, liver, renal (creatinine >2.0 mg/ml) or cardiac illness
- Patients who are unable to clearly identify and rate their symptoms of nausea.
- Women who are pregnant or lactating
- Patients who have a significant abnormality on clinical examination that may, in

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01212484
Principal Investigator: | Horacio C Kaufmann, M.D. | NYU Langone Health |
Responsible Party: | NYU Langone Health |
ClinicalTrials.gov Identifier: | NCT01212484 |
Other Study ID Numbers: |
09-0011 |
First Posted: | September 30, 2010 Key Record Dates |
Results First Posted: | March 28, 2016 |
Last Update Posted: | March 28, 2016 |
Last Verified: | March 2016 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Primary Dysautonomias Autonomic Nervous System Diseases Dysautonomia, Familial Vomiting Signs and Symptoms, Digestive Nervous System Diseases Hereditary Sensory and Autonomic Neuropathies Nervous System Malformations Heredodegenerative Disorders, Nervous System Neurodegenerative Diseases Polyneuropathies Peripheral Nervous System Diseases |
Neuromuscular Diseases Congenital Abnormalities Genetic Diseases, Inborn Carbidopa Antiparkinson Agents Anti-Dyskinesia Agents Dopamine Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Physiological Effects of Drugs Aromatic Amino Acid Decarboxylase Inhibitors Enzyme Inhibitors |