Carbidopa 25mg tablets
Requires a prescription from a doctor or prescriber
Carbidopa presents a chemical denomination of N-amino-alpha-methyl-3-hydroxy-L-tyrosine monohydrate.
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
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Drug safety updates
MHRA alerts for Carbidopa
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Suspected adverse reactions reported for Carbidopa
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Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
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Suspected adverse reactions reported for Carbidopa
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1 branded products available
NHS prescribing volume and spending trends
Guidelines from the National Institute for Health and Care Excellence
NICE clinical guidance(2)
Foslevodopa–foscarbidopa for treating advanced Parkinson's with motor symptoms (TA934)
Parkinson's disease in adults (NG71)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
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Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & safety information
Official UK regulator monitoring and safety alerts
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. Shortage and safety information sourced from MHRA drug safety updates (gov.uk, Crown Copyright under OGL v3.0).
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0.
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Academic studies and reviews for this medicine's active substance
Showing the 50 most relevant studies.
Reviews & meta-analyses: 17 · Randomised trials: 11 · 1985–2026
Showing the 50 most relevant studies, sorted by most relevant.
R. Hauser, A. Hsu, S. Kell, et al.
The Lancet. Neurology, 2013
Burton M, Marsden D, Harish D, et al.
2026
- Parkinson Disease
- Levodopa
- Carbidopa
BackgroundMany Parkinson's disease patients receiving oral levodopa/carbidopa experience a troublesome wearing off effect. Higher doses to mitigate OFF-time are limited by adverse effects occurring at peak dopamine levels, particularly dyskinesia. A novel strategy to reduce OFF-time without increasing peak dopamine levels is the continuous subcutaneous infusion of levodopa/carbidopa, or their prodrug equivalents foslevodopa/foscarbidopa.ObjectivesAssess whether subcutaneous infusion therapies safely reduce OFF-time and improve quality of life scores compared to oral levodopa/carbidopa.MethodsWe searched MEDLINE, Embase, CENTRAL and ICTRP up to 28th October 2024 for clinical trials comparing subcutaneous infusions of levodopa or foslevodopa to oral levodopa in Parkinson's disease.ResultsScreening of 1114 records identified seven studies in which 725 patients received subcutaneous infusion regimens of levodopa/carbidopa (ND0612) (407 patients) or foslevodopa/foscarbidopa (318 patients). Moderate quality evidence indicated subcutaneous infusion reduced the daily duration of OFF-time by 1.98 h (p = 0.0004). Moderate quality evidence indicated improvements in health-related quality of life score PDQ-39 (p = 0.0003) and sleep score PDSS-2 (p = 0.02), but an increase in the rate of treatment-emergent adverse events, mostly related to the infusion site (p = 0.04).ConclusionsSubcutaneous infusion therapies produce a clinically and statistically significant reduction in the duration of OFF-time experienced by patients with Parkinson's disease, compared to oral levodopa/carbidopa. Patient experience is improved by a statistically, but not clinically, significant degree. There are increased adverse events, mostly related to the infusion site. Overall, subcutaneous infusion regimens could provide a meaningful alternative for Parkinson's disease patients who experience severe motor fluctuations with existing levodopa formulations.
Abstract licence: CC BY
Attar A, Aljadani HH, Barwais KF, et al.
2026
- Parkinson Disease
- Levodopa
- Carbidopa
Libo Wang, Jia Li, Jiajun Chen
Frontiers in Neurology, 2018
A. Espay, Fabrizio Stocchi, Rajesh Pahwa, et al.
The Lancet. Neurology, 2024
R. Hauser, A. Espay, A. Ellenbogen, et al.
JAMA Neurology, 2023
H. Baishya
Journal of Developing Drugs, 2017
A. Antonini, W. Poewe, K. Chaudhuri, et al.
Parkinsonism & related disorders, 2017
E. Freire-Álvarez, E. Kurča, L. López Manzanares, et al.
Movement Disorders, 2021
R. Pahwa, K. Lyons, R. Hauser, et al.
Parkinsonism & related disorders, 2014
Sources: aggregated from Europe PMC (EMBL-EBI), OpenAlex, Crossref, PubMed and other open scholarly databases. Retracted articles are excluded. Study information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
173 found
Half-life
107 minutes
Mechanism
Carbidopa is an inhibitor of the DDC which in order, inhibits the peripheral metabolism of levodopa.
Food interactions
None known
Human targets
1 target
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
40-70%
[L5116]
…
Half-life
107 minutes
[A173944]
Protein binding
76%
Volume of distribution
3.6 L/kg
Metabolism
Elimination
66%
Clearance
51.7 L/h
[A173947]
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
The first approved product by the FDA containing only carbidopa was developed by Amerigens Pharmaceuticals Ltd and approved on 2014.[L5110] On the other hand, the combination treatment of carbidopa/levodopa was originally developed by Watson Labs but the historical information by the FDA brings back to the approval of this combination therapy developed by Mayne Pharma in 1992.[L5113]
The combination therapy is administered for the reduction of [levodopa]-driven nausea and vomiting.[FDA label]
The product of carbidopa should be used in patients where the combination therapy of carbidopa/[levodopa] provide less than the adequate daily dosage.[FDA label]
As well carbidopa can be used in patients where the dosages of carbidopa and [levodopa] require individual titration.[FDA label]
Known interactions with other medicines. Always consult a healthcare professional.
Showing 50 of 942 interactions
No reports of overdosage have been registered with the carbidopa-only product. In the event of overdosage, immediate gastric lavage is recommended as well as intravenous fluid administration. Continuous electrocardiographic monitoring is required.[FDA label]
DDC can be found in the body periphery and in the blood-brain barrier.[A13607] The action of carbidopa is focused on peripheral DDC as this drug cannot cross the blood-brain barrier.[T28] Hence, it will prevent the metabolism of [levodopa] in the periphery but it will not have any activity on the generation of dopamine in the brain.
The presence of additional units of circulating [levodopa] can increase the effectiveness of the still functional dopaminergic neurons and it has been shown to alleviate symptoms for a time. The action of carbidopa is very important as [levodopa] is able to cross the blood-brain barrier while dopamine cannot.[T28] Hence the administration of carbidopa is essential to prevent the transformation of external [levodopa] to dopamine before reaching the main action site in the brain.
The coadministration of carbidopa with [levodopa] has been shown to increase the half-life of [levodopa] more than 1.5 times while increasing the plasma level and decreasing clearance. The combination therapy has also shown an increase of the recovery of [levodopa] in urine instead of dopamine which proves a reduced metabolism. This effect has been highly observed by a significant reduction in [levodopa] requirements and a significant reduction in the presence of side effects such as nausea. It has been observed that the effect of carbidopa is not dose-dependent.[T394]
How the body processes this drug — absorption, distribution, metabolism, and elimination
[L5116]
Once absorbed, carbidopa shows bioavailability of 58%.
[A173941]
A maximum concentration of 0.085 mcg/ml was achieved after 143 min with an AUC of 19.28 mcg.min/ml.
[A173944]
[A173944]
[A173947]
However, carbidopa is widely distributed in the tissues, except in the brain.
[L5116]
After one hour, carbidopa is found mainly in the kidney, lungs, small intestine and liver.
[A274]
[A274]
[A274]
[A173947]
Proteins and enzymes this drug interacts with in the body
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
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Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Carbidopa
Additional database identifiers
Drugs Product Database (DPD)
2370
ChemSpider
31640
BindingDB
50418773
PDB
142
ZINC
ZINC000019168887
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2719
GenAtlas
DDC
GeneCards
DDC
GenBank Gene Database
M76180
GenBank Protein Database
181521
UniProt Accession
DDC_HUMAN
DrugBank citations
If you use DrugBank data in your research, please cite:
- DrugBank 6.02024Recommended citationKnox C., Wilson M., Klinger C.M., et alDrugBank 6.0: the DrugBank Knowledgebase for 2024Nucleic Acids Res. 2024 Jan 552(D1):D1265-D1275
- DrugBank 5.02018Wishart D.S., Feunang Y.D., Guo A.C., et alDrugBank 5.0: a major update to the DrugBank database for 2018Nucleic Acids Res. 2017 Nov 846(D1):D1074-D1082
- DrugBank 4.02014Law V., Knox C., Djoumbou Y., et alDrugBank 4.0: shedding new light on drug metabolismNucleic Acids Res. 2014 Jan 142(1):D1091-7
- DrugBank 3.02011Knox C., Law V., Jewison T., et alDrugBank 3.0: a comprehensive resource for 'omics' research on drugsNucleic Acids Res. 2011 Jan39(Database issue):D1035-41
- DrugBank 2.02008Wishart D.S., Knox C., Guo A.C., et alDrugBank: a knowledgebase for drugs, drug actions and drug targets.Nucleic Acids Research2008 Jan36(Database issue):D901-6
- DrugBank 1.02006Wishart D.S., Knox C., Guo A.C., et alDrugBank: a comprehensive resource for in silico drug discovery and exploration.Nucleic Acids Research2006 Jan 134(Database issue):D668-72