TheraRadar
Data updated: May 26, 2026

LODOSYN (carbidopa)

DOPA Decarboxylase Inhibitors
CNS Approved 1977-04-25

Lodosyn (carbidopa) is indicated for use in combination with levodopa or carbidopa-levodopa to treat symptoms of idiopathic Parkinson’s disease, postencephalitic parkinsonism, and symptomatic parkinsonism (such as that following carbon monoxide or manganese intoxication). It is specifically utilized for patients whose current carbidopa-levodopa regimen provides an inadequate daily dose of carbidopa (usually less than 70 mg) or for those requiring individualized titration of each medication. The addition of Lodosyn permits lower levodopa dosing, which reduces peripheral side effects like nausea and vomiting and may provide a smoother therapeutic response. However, it has not been shown to benefit patients with markedly irregular (“on-off”) responses to levodopa.

Source: FDA Label • ATON • Aromatic Amino Acid Decarboxylation Inhibitor

How LODOSYN Works

Parkinson’s disease symptoms are associated with dopamine depletion in the corpus stri

1
Indication
--
Phase 3 Trials
1
Priority Reviews
49
Years on Market

Details

Status
Prescription
First Approved
1977-04-25
Routes
ORAL
Dosage Forms
TABLET

Companies

Active Ingredient: CARBIDOPA

LODOSYN Approval History

1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
24 FDA actions from 1977 to 2014
Feb 2014 SUPPL
Label · Labeling
Dec 2002 SUPPL Priority
Mfg · Manufacturing (CMC)
Sep 2002 SUPPL Priority
Mfg · Manufacturing (CMC)

What LODOSYN Treats

2 indications

LODOSYN is approved for 2 conditions since its original approval in 1977. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Parkinson's Disease
  • Parkinsonism
Source: FDA Label

LODOSYN Competitive Set

Pro

Three rings of competition based on shared molecular targets and treated indications.

Unlock 8 more competitors across all three rings.
Upgrade to Pro

Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

Drugs Similar to LODOSYN

3 of 20

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

CREXONT
CARBIDOPA
2 shared
IMPAX
Shared indications:
Parkinson's DiseaseParkinsonism
DHIVY
CARBIDOPA
2 shared
AVION PHARMS
Shared indications:
Parkinson's DiseaseParkinsonism
RYTARY
CARBIDOPA
2 shared
IMPAX
Shared indications:
Parkinson's DiseaseParkinsonism
📋

Clinical Trial Registry

18 trials
Trial Sponsor ID Phase Status Title
NCT04520178 5-HTP only Pro00119483/00125176 Ph 2, Ph 3 recruiting Effects of 5HTP on the Injured Human Spinal Cord
NCT04325503 RES results posted HUM00156490 5U01AG061393-05 Ph 1, Ph 2 completed Neurobiological Drivers of Mobility Resilience: The Dopaminergic System
NCT01323374 FMS201 Droxidopa FMS201 Ph 2 completed Study To Assess The Clinical Benefit Of Droxidopa And Droxidopa/Carbidopa In Subjects With Fibromyalgia
NCT04000919 18.1268 Ph 2, Ph 3 suspended Effects of 5HTP and LDOPA on CNS Excitability After SCI
NCT00685919 results posted 101499 HL071784-05A1 Ph 2, Ph 3 completed Peripheral Dopamine in Postural Tachycardia Syndrome
NCT04764383 20201550 Ph 2 withdrawn Histaminergic Basis of Fatigue in Multiple Sclerosis
NCT03055936 COMDOS1 results posted 3112005 Ph 1 completed Dose-finding Pharmacokinetic Study in Healthy Males
NCT03266965 20161186 W81XWH-16-1-0462 Ph 1 completed Histaminergic Basis of Central Fatigue in Multiple Sclerosis - A Novel Approach
NCT03115827 results posted VUMC54580 Ph 4 completed Norepinephrine-targeted Therapy for Action Control in Parkinson Disease
NCT01399905 results posted IRB00004133 Ph 2 completed High and Low Dose Carbidopa Treatment of Parkinson's Disease
NCT00845000 results posted P05550 MK-3814-023 Ph 1 completed Acute Effects of Preladenant (SCH 420814) on Dyskinesia and Parkinsonism in Levodopa Treated Participants (P05550)
NCT02633839 CVT-301-007 Ph 1 completed A Study of the Safety and Levodopa Pharmacokinetics Following Single Dose Administration of CVT 301 (Levodopa Inhalation Powder) in Smoking and Non-Smoking Adults
NCT02633007 CVT-301-008 Ph 1 completed A Study of the Safety and Pharmacokinetics of Levodopa Following Administration of CVT 301 (Levodopa Inhalation Powder) in Adults With Asthma
NCT01212484 results posted 09-0011 Ph 3 completed Carbidopa for the Treatment of Nausea and Vomiting in Familial Dysautonomia
NCT01227655 BIPARKII results posted BIA-91067-302 2010-022366-27, BIA-91067-302 Ph 3 completed Efficacy and Safety of BIA 9-1067 in Idiopathic Parkinson's Disease Patients.
NCT01568073 results posted BIA-91067-301 2010-021860-13 Ph 3 completed Efficacy and Safety of BIA 9-1067 in Idiopathic Parkinson's Disease Patients With "Wearing-off" Phenomenon
NCT01229332 ND0611/002 Ph 1, Ph 2 completed A Safety, Tolerability and Pharmacokinetic Study of ND0611 on the Top of Different Oral Dosage Forms of Levodopa/Carbidopa in Parkinson's Disease Patients
NCT01296464 PARTEST 2939136 Ph 2 completed Comparing Different Levodopa/Carbidopa/Entacapone Treatment Regimens
🔬

Active Pipeline

Pro

Ongoing clinical trials by development phase

Loading...

Key Completed Trials

Pro

Completed studies with published results, ranked by significance

Loading...
📊

Trial Timeline

Full development history with FDA approval milestones

|
Loading...
Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

LODOSYN FDA Label Details

Indications & Usage

FDA Label (PDF)

LODOSYN is indicated for the treatment of Parkinson's Disease; Parkinsonism.

Track LODOSYN with TheraRadar Pro

Watchlist alerts, full database access, CSV exports across 14,000+ drugs.

Upgrade to Pro

Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.