Prescription medicine
Carbidopa Brand names: Lodosyn
Carbidopa (Lodosyn) is a prescription medicine with an FDA approval on record since 1977. FDA's NDC Directory lists it from 7 generic labelers, and pharmacies paid $0.536 per carbidopa 25 mg tablet in the October 7, 2026 NADAC survey.
- Generic listed
Check it at the source: the carbidopa FDA label on DailyMed (effective July 2, 2020, Oceanside Pharmaceuticals); the NDA 17830 record on Drugs@FDA; every carbidopa label on DailyMed.
Highlights of the record
FDA label of July 2, 2020; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Used for
From the label: indications and usageCarbidopa tablets are indicated for use with carbidopa-levodopa or with levodopa in the treatment of the symptoms of idiopathic Parkinson’s disease (paralysis agitans), postencephalitic parkinsonism, and symptomatic parkinsonism, which may follow injury to the nervous system by carbon monoxide intoxication and/or manganese intoxication.
Forms and strengths
- 25 mg
Tablet.
On the market
- Earliest approval on file
- April 25, 1977 Lodosyn, Aton; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 7 first March 10, 2014; 5 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 9 of which 7 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- $0.536 per tablet Carbidopa 25 mg tablet
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 3,071 through July 30, 2026
What is carbidopa used for?
From the label: indications and usageCarbidopa tablets are indicated for use with carbidopa-levodopa or with levodopa in the treatment of the symptoms of idiopathic Parkinson’s disease (paralysis agitans), postencephalitic parkinsonism, and symptomatic parkinsonism, which may follow injury to the nervous system by carbon monoxide intoxication and/or manganese intoxication. Carbidopa is for use with carbidopa-levodopa in patients for whom the dosage of carbidopa-levodopa provides less than adequate daily dosage (usually 70 mg daily) of carbidopa. Carbidopa is for use with levodopa in the occasional patient whose dosage requirement of carbidopa and levodopa necessitates separate titration of each medication. […]
Conditions named in the indications of carbidopa's FDA labels, with every medicine labeled for each:
From other carbidopa labelsParkinson's disease: INDICATIONS AND USAGE Carbidopa tablets are indicated for use with carbidopa-levodopa or with levodopa in the treatment of the symptoms of idiopathic Parkinson’s disease (paralysis agitans), postencephalitic parkinsonism, and symptomatic …
FDA pharmacologic class: Aromatic Amino Acid Decarboxylation Inhibitor.
Source: FDA drug label (Carbidopa), NDA017830 (Aton), as published by Oceanside Pharmaceuticals, effective July 2, 2020 (SPL set d5204e5e-10ef-4758-8fc6-cb710048c687), via openFDA; the full label on DailyMed
Is there a generic for carbidopa (Lodosyn)?
The FDA approved the first generic carbidopa on March 10, 2014. 7 generic applications are approved; 5 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists carbidopa from 7 labelers under a generic (ANDA) application and from 1 brand labeler. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1977 earliest approval on file
- 2014 first generic approved
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for carbidopa (Lodosyn)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $0.536 per Carbidopa 25 mg tablet, down 25% from $0.711 on October 8, 2025. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Carbidopa 25 mg tablet (generic)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Carbidopa 25 mg tablet | Generic | $0.536 per tablet | $16.08 | -25% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
What does the carbidopa label say about other medicines?
The carbidopa label names 8 other medicines in its interaction, contraindication or warning sections. The labels of 5 other medicines name carbidopa. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Bromocriptine | warnings | Dopamine agonists, such as bromocriptine, and muscle relaxants, such as dantrolene, are often used in the treatment of NMS; however, their effectiveness has not been demonstrated in controlled studies. |
| Dantrolene | warnings | Dopamine agonists, such as bromocriptine, and muscle relaxants, such as dantrolene, are often used in the treatment of NMS; however, their effectiveness has not been demonstrated in controlled studies. |
| Isoniazid | drug interactions | Dopamine D 2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone) and isoniazid may reduce the therapeutic effects of levodopa. |
| Levodopa | contraindications | Nonselective monoamine oxidase (MAO) inhibitors are contraindicated for use with levodopa or carbidopa-levodopa combination products with or without carbidopa. |
| Metoclopramide | drug interactions | Although metoclopramide may increase the bioavailability of levodopa by increasing gastric emptying, metoclopramide may also adversely affect disease control by its dopamine receptor antagonistic properties. |
| Phenytoin | drug interactions | In addition, the beneficial effects of levodopa in Parkinson’s disease have been reported to be reversed by phenytoin and papaverine. |
| Risperidone | drug interactions | Dopamine D 2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone) and isoniazid may reduce the therapeutic effects of levodopa. |
| Selegiline | contraindications | Carbidopa-levodopa, or levodopa may be administered concomitantly with the manufacturer’s recommended dose of an MAO inhibitor with selectivity for MAO type B (e.g., selegiline HCl) (see PRECAUTIONS, Drug Interactions ). |
Other labels that name carbidopa
Source: FDA drug label (Carbidopa), NDA017830 (Aton), as published by Oceanside Pharmaceuticals, effective July 2, 2020 (SPL set d5204e5e-10ef-4758-8fc6-cb710048c687), via openFDA; the full label on DailyMed
What do FAERS reports show for carbidopa?
The FDA Adverse Event Reporting System holds 3,071 reports that list carbidopa among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 469 are coded as a death and 924 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as carbidopa?
11 other medicines are given the same way (oral) and in the same FDA class as carbidopa or labeled mainly for the same use (parkinson's disease), the same class first. Parkinson's disease lists all 19 medicines labeled for it, by any route. The first 8 are below. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Ropinirole | Parkinson's disease | 27 labelers | $0.046 per tablet 0.25 mg tablet | No current entry |
| Pramipexole | Parkinson's disease | 22 labelers | $0.0452 per tablet 0.25 mg tablet | No current entry |
| Benztropine | Parkinson's disease | 19 labelers | $0.0753 per tablet 1 mg tablet | A presentation being discontinued |
| Rasagiline | Parkinson's disease | 14 labelers | $0.521 per tablet 0.5 mg tablet | No current entry |
| Trihexyphenidyl | Parkinson's disease | 8 labelers | $0.0884 per tablet 2 mg tablet | No current entry |
| Entacapone | Parkinson's disease | 11 labelers | $0.325 per tablet 200 mg tablet | No current entry |
| Selegiline | Parkinson's disease | 11 labelers | $0.756 per capsule 5 mg capsule | No current entry |
| Bromocriptine | Parkinson's disease | 6 labelers | $1.61 per tablet 2.5 mg tablet | No current entry |
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
What next?
- Alternatives to carbidopa
- 11 medicines for the same use
- Other aromatic amino acid decarboxylation inhibitors
- the pharmacologic class, with prices and generics
- Carbidopa side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other