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ClinicalTrials.gov public records Last synced Oct 23, 2026, 8:33 PM EDT

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Showing 1–24 of 37 matching trials from the live ClinicalTrials.gov search.
Filters: Intervention: Methyldopa Clear all
Completed Phase 2 Interventional Results available

Carbidopa for the Treatment of Excessive Blood Pressure Variability

NCT02553265
View directory record Official record
Conditions
Dysautonomia, Familial, Baroreflex Failure Syndrome
Interventions
Carbidopa Low-Dose, Placebo, Carbidopa High-Dose
Drug · Other
Lead sponsor
NYU Langone Health
Other
Eligibility
10 Years to 60 Years
Enrollment
22 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2015 – 2019
U.S. locations
2
States / cities
New York, New York
Source: ClinicalTrials.gov public record
Updated Feb 9, 2022 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional Accepts healthy volunteers

Autonomic Nervous System and Chronic Fatigue Syndrome

NCT00580619
View directory record Official record
Conditions
Chronic Fatigue Syndrome, Orthostatic Intolerance, Postural Tachycardia Syndrome
Interventions
Autonomic Function Testing, Saline infusions, L-NMMA trimethaphan, methyldopa
Other · Drug
Lead sponsor
Vanderbilt University
Other
Eligibility
18 Years to 65 Years
Enrollment
170 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2007 – 2017
U.S. locations
1
States / cities
Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated Jan 18, 2017 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 2 Interventional

A Efficacy, Safety and Pharmacokinetic Study of XP21279 and Sinemet® in Parkinson's Disease Subjects

NCT01171313
View directory record Official record
Conditions
Parkinson's Disease
Interventions
XP21279 and carbidopa (experimental), Sinemet (comparator), Placebo for XP21279 and carbidopa, Placebo for Sinemet
Drug
Lead sponsor
XenoPort, Inc.
Industry
Eligibility
30 Years to 80 Years
Enrollment
35 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2010 – 2011
U.S. locations
12
States / cities
Phoenix, Arizona • Little Rock, Arkansas • Long Beach, California + 9 more
Source: ClinicalTrials.gov public record
Updated Feb 18, 2021 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1Phase 2 Interventional Results available

Neurobiological Drivers of Mobility Resilience: The Dopaminergic System - Supplemental Open-Label Arm

NCT06587217
View directory record Official record
Conditions
Parkinsonian Signs in Older Persons
Interventions
Carbidopa 25 mg, Carbidopa-Levodopa 25/100 mg
Drug
Lead sponsor
University of Michigan
Other
Eligibility
60 Years and older
Enrollment
5 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2024 – 2025
U.S. locations
2
States / cities
Ann Arbor, Michigan
Source: ClinicalTrials.gov public record
Updated Apr 14, 2026 · Synced Oct 23, 2026, 8:33 PM EDT
Suspended Phase 2Phase 3 Interventional

Effects of 5HTP and LDOPA on CNS Excitability After SCI

NCT04000919
View directory record Official record
Conditions
Spinal Cord Injuries
Interventions
5HTP, L-DOPA, Placebo oral tablet, Carbidopa
Drug
Lead sponsor
Jessica M D'Amico
Other
Eligibility
18 Years to 65 Years
Enrollment
30 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2019 – 2023
U.S. locations
1
States / cities
Louisville, Kentucky
Source: ClinicalTrials.gov public record
Updated Oct 17, 2022 · Synced Oct 23, 2026, 8:33 PM EDT
Withdrawn Phase 2 Interventional Accepts healthy volunteers

Histaminergic Basis of Fatigue in Multiple Sclerosis

NCT04764383
View directory record Official record
Conditions
Multiple Sclerosis
Interventions
L-Histidine, Placebo, Lodosyn
Drug
Lead sponsor
University of Miami
Other
Eligibility
18 Years to 60 Years
Healthy volunteers
Accepts healthy volunteers
Timeline
2022
U.S. locations
1
States / cities
Miami, Florida
Source: ClinicalTrials.gov public record
Updated Jul 29, 2021 · Synced Oct 23, 2026, 8:33 PM EDT
Completed No phase listed Observational

ACEI or ARB and COVID-19 Severity and Mortality in US Veterans

NCT04467931
View directory record Official record
Conditions
Hypertension, COVID
Interventions
ACEI/ARB, Non-ACEI/ARB, ACEI, ARB
Drug
Lead sponsor
University of Utah
Other
Eligibility
18 Years and older
Enrollment
22,213 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2020
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Apr 28, 2021 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

A Study of the Safety and Pharmacokinetics of Levodopa Following Administration of CVT 301 (Levodopa Inhalation Powder) in Adults With Asthma

NCT02633007
View directory record Official record
Conditions
Asthma
Interventions
CVT-301 (levodopa inhalation powder), Carbidopa, Placebo
Drug · Other
Lead sponsor
Acorda Therapeutics
Industry
Eligibility
25 Years to 65 Years
Enrollment
25 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2015 – 2016
U.S. locations
3
States / cities
Daytona Beach, Florida • North Dartmouth, Massachusetts • Dallas, Texas
Source: ClinicalTrials.gov public record
Updated Jun 13, 2016 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

Behavioral and Physiological Effects of Cocaine in Cocaine-dependent Participants Treated With Levodopa in Combination With Carbidopa and Entacapone (LCE)

NCT01437293
View directory record Official record
Conditions
Cocaine Abuse
Interventions
L-dopa / carbidopa / entacapone (LCE)
Drug
Lead sponsor
New York State Psychiatric Institute
Other
Eligibility
21 Years to 50 Years
Enrollment
15 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2010 – 2012
U.S. locations
1
States / cities
New York, New York
Source: ClinicalTrials.gov public record
Updated May 21, 2018 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Not applicable Interventional Results available

Effect of Methyldopa on MHC Class II Antigen Presentation in Type 1 Diabetes

NCT01883804
View directory record Official record
Conditions
Diabetes Mellitus, Type 1
Interventions
Methyldopa
Drug
Lead sponsor
University of Colorado, Denver
Other
Eligibility
18 Years to 46 Years
Enrollment
30 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2013 – 2016
U.S. locations
1
States / cities
Aurora, Colorado
Source: ClinicalTrials.gov public record
Updated Jan 18, 2022 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 3 Interventional Results available

A Study Comparing Efficacy of Levodopa-Carbidopa Intestinal Gel/Carbidopa-Levodopa Enteral Suspension and Optimized Medical Treatment on Dyskinesia in Subjects With Advanced Parkinson's Disease (DYSCOVER)

NCT02799381
View directory record Official record
Conditions
Parkinson's Disease (PD)
Interventions
Optimized antiparkinsonian treatment, Levodopa-Carbidopa Intestinal Gel (LCIG), CADD-Legacy ambulatory infusion pump, Percutaneous endoscopic gastrostomy tube, Jejunal extension tube
Drug · Device
Lead sponsor
AbbVie
Industry
Eligibility
30 Years and older
Enrollment
63 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2017 – 2019
U.S. locations
2
States / cities
Port Charlotte, Florida • Round Rock, Texas
Source: ClinicalTrials.gov public record
Updated Aug 18, 2020 · Synced Oct 23, 2026, 8:33 PM EDT
Terminated Phase 4 Interventional Results available

L-DOPA vs. Placebo for Depression and Psychomotor Slowing in Older Adults

NCT03761030
View directory record Official record
Conditions
Major Depressive Disorder, Dysthymia, Depression
Interventions
L-DOPA, Placebo Oral Tablet
Drug
Lead sponsor
New York State Psychiatric Institute
Other
Eligibility
60 Years and older
Enrollment
51 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2019 – 2021
U.S. locations
1
States / cities
New York, New York
Source: ClinicalTrials.gov public record
Updated May 22, 2023 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 2 Interventional Accepts healthy volunteers

Dopaminergic Dysfunction in Late-Life Depression

NCT04469959
View directory record Official record
Conditions
Late Life Depression, Cognitive Decline, Depressive Disorder, Treatment-Resistant, Levodopa, Gait Impairment
Interventions
L-Dopa, Placebo
Drug
Lead sponsor
Vanderbilt University Medical Center
Other
Eligibility
60 Years and older
Enrollment
79 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2021 – 2026
U.S. locations
2
States / cities
Pittsburgh, Pennsylvania • Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated Aug 6, 2026 · Synced Oct 23, 2026, 8:33 PM EDT
Withdrawn Phase 1Phase 2 Interventional Accepts healthy volunteers

Treatment Targets for Chronic Hypertension in Pregnancy

NCT00194974
View directory record Official record
Conditions
Pregnancy Toxemia, Hypertension, Proteinuria
Interventions
methyldopa, labetalol, nifedipine, clonidine
Drug
Lead sponsor
Weill Medical College of Cornell University
Other
Eligibility
18 Years to 50 Years · Female only
Healthy volunteers
Accepts healthy volunteers
Timeline
2004 – 2005
U.S. locations
1
States / cities
New York, New York
Source: ClinicalTrials.gov public record
Updated Jan 30, 2017 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional Results available

Study on Tolerability of Levodopa/Carbidopa in Children With Angelman Syndrome

NCT00829439
View directory record Official record
Conditions
Angelman Syndrome
Interventions
Levodopa/Carbidopa (4:1)
Drug
Lead sponsor
Boston Children's Hospital
Other
Eligibility
4 Years to 12 Years
Enrollment
16 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2009 – 2010
U.S. locations
1
States / cities
Boston, Massachusetts
Source: ClinicalTrials.gov public record
Updated Nov 21, 2016 · Synced Oct 23, 2026, 8:33 PM EDT
Terminated Phase 1Phase 2 Interventional Accepts healthy volunteers Results available

Augmenting Effects of L-DOPS With Carbidopa and Entacapone

NCT00547911
View directory record Official record
Conditions
Parkinson Disease, Multiple System Atrophy, Autonomic Nervous System Diseases
Interventions
Droxidopa, Carbidopa, Entacapone
Drug
Lead sponsor
National Institute of Neurological Disorders and Stroke (NINDS)
NIH
Eligibility
18 Years and older
Enrollment
14 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2007 – 2013
U.S. locations
1
States / cities
Bethesda, Maryland
Source: ClinicalTrials.gov public record
Updated Jul 17, 2014 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 4 Interventional Results available

Apokyn for Motor IMProvement of Morning AKinesia Trial (AM IMPAKT)

NCT01770145
View directory record Official record
Conditions
Parkinson's Disease, Motor Symptoms, Akinesia, Hypomobility, Delayed Levodopa Onset
Interventions
APOKYN, L-dopa, Trimethobenzamide
Drug
Lead sponsor
MDD US Operations, LLC a subsidiary of Supernus Pharmaceuticals
Industry
Eligibility
18 Years and older
Enrollment
127 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2012 – 2014
U.S. locations
12
States / cities
Los Angeles, California • Reseda, California • Washington D.C., District of Columbia + 9 more
Source: ClinicalTrials.gov public record
Updated Aug 14, 2023 · Synced Oct 23, 2026, 8:33 PM EDT
Recruiting Phase 1 Interventional Accepts healthy volunteers

[18F]F-DOPA Imaging in Patients With Autonomic Failure

NCT04246437
View directory record Official record
Conditions
Autonomic Failure, Pure Autonomic Failure, Parkinson Disease, Multiple System Atrophy, Dementia With Lewy Bodies
Interventions
[18F]FDOPA, Carbidopa 200mg oral dose, Entacapone 400mg oral dose
Drug
Lead sponsor
Daniel Claassen
Other
Eligibility
18 Years and older
Enrollment
40 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2020 – 2027
U.S. locations
1
States / cities
Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated Mar 16, 2026 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

The Pathophysiology of Orthostatic Hypotension

NCT00748059
View directory record Official record
Conditions
Autonomic Nervous System Diseases, Orthostatic Hypotension, Dopamine Beta-Hydroxylase Deficiency, Orthostatic Intolerance
Interventions
Standing or upright tilt, Microneurography, QSweat, neck cuff stimulation, phenylephrine,isoproterenol,nitroprusside,propranolol,edrophonium,atropine,tyramine, clonidine,yohimbine,metoclopramide,alpha-methyldopa, BodPod, Eye exam, Sleep study, Pain response testing, Metabolic chamber, Brain function studies, Bicycle Exercise Test
Procedure · Device · Drug
Lead sponsor
Vanderbilt University Medical Center
Other
Eligibility
12 Years to 70 Years
Enrollment
10 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
1996 – 2020
U.S. locations
1
States / cities
Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated May 12, 2021 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

Measuring Parkinson's Disease Progression

NCT03205956
View directory record Official record
Conditions
Parkinson's Disease
Interventions
Levodopa
Drug
Lead sponsor
Kevin J. Black, MD
Other
Eligibility
40 Years to 79 Years
Enrollment
31 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2017 – 2019
U.S. locations
1
States / cities
St Louis, Missouri
Source: ClinicalTrials.gov public record
Updated Oct 14, 2022 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

Multiple Ascending Dose (MAD) Study of IMT-002 in HLA-DQ8-positive Type 1 Diabetes

NCT04625595
View directory record Official record
Conditions
Type1 Diabetes
Interventions
350mg BID (700mg total daily) IMT-002, D-methyldopa, active formulation in capsule or Placebo, microcrystalline cellulose in capsule, 700mg BID (1400mg total daily) IMT-002, D-methyldopa, active formulation in capsule or Placebo, microcrystalline cellulose in capsule, 1050mg QD (1050mg total daily) IMT-002, D-methyldopa, active formulation in capsule or Placebo, microcrystalline cellulose in capsule, 1050mg BID (2100mg total daily) IMT-002, D-methyldopa, active formulation in capsule or Placebo, microcrystalline cellulose in capsule
Drug
Lead sponsor
Immunomolecular Therapeutics, Inc.
Industry
Eligibility
18 Years to 45 Years
Enrollment
30 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2020 – 2021
U.S. locations
3
States / cities
Chula Vista, California • Aurora, Colorado • Renton, Washington
Source: ClinicalTrials.gov public record
Updated Aug 25, 2021 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 3 Interventional Results available

Study Comparing Continuous Subcutaneous Infusion Of ABBV-951 With Oral Carbidopa/Levodopa Tablets For Treatment Of Motor Fluctuations In Adult Participants With Advanced Parkinson's Disease

NCT04380142
View directory record Official record
Conditions
Parkinson's Disease (PD)
Interventions
ABBV-951, Placebo for Levodopa/Carbidopa (LD/CD), Levodopa/Carbidopa (LD/CD), Placebo for ABBV-951
Drug
Lead sponsor
AbbVie
Industry
Eligibility
30 Years and older
Enrollment
174 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2020 – 2021
U.S. locations
70
States / cities
Birmingham, Alabama • Mobile, Alabama • Phoenix, Arizona + 62 more
Source: ClinicalTrials.gov public record
Updated Nov 18, 2022 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional Accepts healthy volunteers

Histaminergic Basis of Central Fatigue in Multiple Sclerosis - A Novel Approach

NCT03266965
View directory record Official record
Conditions
Multiple Sclerosis
Interventions
Carbidopa, L-Histidine
Drug · Dietary Supplement
Lead sponsor
University of Miami
Other
Eligibility
18 Years to 60 Years
Enrollment
18 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2018 – 2020
U.S. locations
1
States / cities
Miami, Florida
Source: ClinicalTrials.gov public record
Updated Oct 8, 2020 · Synced Oct 23, 2026, 8:33 PM EDT
Completed Phase 1 Interventional

Treatment of Orthostatic Hypotension in Autonomic Failure

NCT00223691
View directory record Official record
Conditions
Autonomic Failure, Orthostatic Hypotension
Interventions
Atomoxetine, Acarbose, Pyridostigmine Bromide, Yohimbine, Midodrine HCl, placebo, Modafinil, Octreotide, water intake, Diphenhydramine Hydrochloride, Ranitidine HCL, Tranylcypromine, Ergotamine/ Caffeine, Celecoxib, Pseudoephedrine, Methylphenidate, Indomethacin, Ibuprofen, Oxymetazoline 0.05% nasal solution, Bovril, Acetazolamide, Rivastigmine tartrate, Carbidopa/levodopa, Inflatable abdominal binder, inflatable abdominal binder (sham)
Drug · Other · Dietary Supplement + 1 more
Lead sponsor
Vanderbilt University
Other
Eligibility
18 Years to 85 Years
Enrollment
389 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2002 – 2017
U.S. locations
1
States / cities
Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated Jan 18, 2017 · Synced Oct 23, 2026, 8:33 PM EDT