CARBIDOPA AND LEVODOPA 25 mg; 250 mg Tablet, 500-count
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the Aromatic Amino Acid Decarboxylation Inhibitor class.
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🏭 Manufacturer & labeler
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🩺 Clinical
- Levodopa is the medicine that actually works in your brain — it crosses into the brain and gets converted into dopamine, the chemical that Parkinson's disease depletes. The problem...
- What exactly does levodopa and carbidopa do, and why do I need both?
- Generally yes, but the timing and content of your meals can matter. High-protein foods — like large servings of meat, eggs, or dairy — can compete with levodopa for absorption in y...
- Can I eat normally while taking this medication?
Patient education
Supplement & herbal interactions
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💊 What it looks like
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
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UNII L06K8R7DQK
A synthetic blue dye approved by the FDA for use in medications and foods. It serves as a colorant to make pills and liquids visually distinct and easier to identify.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII OP1R32D61U
Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
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UNII 5856J3G2A2
A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
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UNII O8232NY3SJ
A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
5 inactive ingredients listed in the exact product block matched to this NDC.
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ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $0.115 | $57.45 / 500 tablets |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $0.1325 | $66.25 / 500 tablets |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Carbidopa and levodopa 25 mg/1; 250 mg 00093-9703-05 | Teva | 500 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 00904-7549-61 | Major | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa And Levodopa 25 mg/1; 250 mg 31722-0383-01 | Camber | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 50228-0459-01 | ScieGen | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa-levodopa 25 mg/1; 250 mg 52817-0392-00 | TruPharma, | 1000 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 59651-0458-01 | Aurobindo | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 60687-0836-01 | American | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 69367-0340-01 | Westminster | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa-levodopa 25 mg/1; 250 mg 72888-0108-00 | Advagen | 1000 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa and Levodopa 25 mg/1; 250 mg 75907-0021-01 | Dr. | 100 tablets | $0.109 | AB | Availability likely | save 5% |
| Carbidopa And Levodopa 25 mg/1; 250 mgthis 62756-0985-02 | Sun | 500 tablets | $0.115 | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 00615-8516-39 | NCS | 30 tablets | — | AB | FDA listed | — |
| Carbidopa and levodopa 25 mg/1; 250 mg 42291-0488-01 | AvKARE | 100 tablets | — | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 55154-0192-00 | Cardinal | 10 tablets | — | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 63629-4134-01 | Bryant | 30 tablets | — | AB | FDA listed | — |
| Carbidopa And Levodopa 25 mg/1; 250 mg 63629-9154-01 | Bryant | 100 tablets | — | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 67046-1450-03 | Coupler | 30 tablets | — | AB | FDA listed | — |
| Carbidopa And Levodopa 25 mg/1; 250 mg 67046-1668-03 | Coupler | 30 tablets | — | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 70518-4620-00 | REMEDYREPACK | 50 tablets | — | AB | FDA listed | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 71205-0879-00 | Proficient | 100 tablets | — | AB | FDA listed | — |
| Carbidopa And Levodopa 25 mg/1; 250 mg 72865-0363-01 | XLCare | 100 tablets | — | AB | FDA listed | — |
| Sinemet 25 mg/1; 250 mg 78206-0167-01 | Organon | 100 tablets | — | AB | Discontinued | — |
| Carbidopa and Levodopa 25 mg/1; 250 mg 67046-1689-03 | Coupler | 30 tablets | — | AB | FDA listed | — |
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⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
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🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
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📦 Packaging — all sizes for this product
| Package NDC | Description | Per unit | Per pack | Marketing start | Status |
|---|---|---|---|---|---|
| 62756-0985-01 | 100 TABLET in 1 BOTTLE (62756-985-01) | $0.1149 / ea | $11.49 | 2021-08-12 | Active |
| 62756-0985-02 You're viewing this | 500 TABLET in 1 BOTTLE (62756-985-02) | $0.1149 / ea | $57.45 | 2021-08-12 | Active |
You're viewing the largest of 2 pack sizes for this product.
This pack effectively ties for the lowest per-ea cost of the 2 priced pack sizes ($0.1149 NADAC).
Pack size FAQ
What quantity is in NDC 62756-0985-02?
What is the difference between NDC 62756-0985-02 and NDC 62756-0985-01?
What NDC number is used to bill for this package of CARBIDOPA AND LEVODOPA 25 mg; 250 mg Tablet?
Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Carbidopa and levodopa tablets, USP are indicated in the treatment of Parkinson's disease, post-encephalitic parkinsonism, and symptomatic parkinsonism that may follow carbon monoxide intoxication or manganese intoxication. Carbidopa allows patients treated for Parkinson's disease to use much lower doses of levodopa. Some patients who responded poorly to levodopa have improved on carbidopa and levodopa tablets, USP.
This is most likely due to decreased peripheral decarboxylation of levodopa caused by administration of carbidopa rather than by a primary effect of carbidopa on the nervous system. Carbidopa has not been shown to enhance the intrinsic efficacy of levodopa. Carbidopa may also reduce nausea and vomiting and permit more rapid titration of levodopa.
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.
Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting. Usual Initial Dosage Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day.
This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached. If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day.
However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached. How to Transfer Patients from Levodopa Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets.
A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1,500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1,500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.
Maintenance Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg.
When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.
Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction.
Blepharospasm may be a useful early sign of excess dosage in some patients. Addition of Other Antiparkinsonian Medications Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required. Interruption of Therapy Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets.
Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS . ) If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mou…
⛔ Contraindications ▾
CONTRAINDICATIONS Nonselective monoamine oxidase (MAO) inhibitors are contraindicated for use with carbidopa and levodopa tablets. These inhibitors must be discontinued at least two weeks prior to initiating therapy with carbidopa and levodopa tablets. Carbidopa and levodopa tablets 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 ).
Carbidopa and levodopa tablets are contraindicated in patients with known hypersensitivity to any component of this drug, and in patients with narrow-angle glaucoma.
⚠️ Warnings ▾
WARNINGS When carbidopa and levodopa tablets are to be given to patients who are being treated with levodopa, levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa tablets is started. In order to reduce adverse reactions, it is necessary to individualize therapy. See DOSAGE AND ADMINISTRATION section before initiating therapy .
The addition of carbidopa with levodopa in the form of carbidopa and levodopa tablets reduces the peripheral effects (nausea, vomiting) due to decarboxylation of levodopa; however, carbidopa does not decrease the adverse reactions due to the central effects of levodopa. Because carbidopa permits more levodopa to reach the brain and more dopamine to be formed, certain adverse central nervous system (CNS) effects, e.g., dyskinesias (involuntary movements), may occur at lower dosages and sooner with carbidopa and levodopa tablets than with levodopa alone.
All patients should be observed carefully for the development of depression with concomitant suicidal tendencies. Carbidopa and levodopa should be administered cautiously to patients with severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease. As with levodopa, care should be exercised in administering carbidopa and levodopa tablets to patients with a history of myocardial infarction who have residual atrial, nodal, or ventricular arrhythmias.
In such patients, cardiac function should be monitored with particular care during the period of initial dosage adjustment, in a facility with provisions for intensive cardiac care. As with levodopa, treatment with carbidopa and levodopa tablets may increase the possibility of upper gastrointestinal hemorrhage in patients with a history of peptic ulcer. Falling Asleep During Activities of Daily Living and Somnolence Patients taking carbidopa and levodopa tablets, USP alone or with other dopaminergic drugs have reported suddenly falling asleep without prior warning of sleepiness while engaged in activities of daily living (includes operation of motor vehicles).
Road traffic accidents attributed to sudden sleep onset have been reported. Although many patients reported somnolence while on dopaminergic medications, there have been reports of road traffic accidents attributed to sudden onset of sleep in which the patient did not perceive any warning signs, such as excessive drowsiness, and believed that they were alert immediately prior to the event. Sudden onset of sleep has been reported to occur as long as one year after the initiation of treatment.
Falling asleep while engaged in activities of daily living usually occurs in patients experiencing preexisting somnolence, although some patients may not give such a history. For this reason, prescribers should reassess patients for drowsiness or sleepiness especially since some of the events occur well after the start of treatment. Prescribers should be aware that patients may not acknowledge drowsiness or sleepiness until directly questioned about drowsiness or sleepiness during specific activities.
Patients should be advised to exercise caution while driving or operating machines during treatment with carbidopa and levodopa tablets, USP. Patients who have already experienced somnolence or an episode of sudden sleep onset should not participate in these activities during treatment with carbidopa and levodopa tablets, USP. Before initiating treatment with carbidopa and levodopa tablets, USP, advise patients about the potential to develop drowsiness and ask specifically about factors that may increase the risk for somnolence with carbidopa and levodopa tablets, USP such as the use of concomitant sedating medications and the presence of sleep disorders.
Consider discontinuing carbidopa and levodopa tablets, USP in patients who report significant daytime sleepiness or episodes of falling asleep during activities that require active participation (e.g., conversations, eating, etc.). If treatme…
🤒 Adverse Reactions ▾
ADVERSE REACTIONS The most common adverse reactions reported with carbidopa and levodopa tablets have included dyskinesias, such as choreiform, dystonic, and other involuntary movements, and nausea. The following other adverse reactions have been reported with carbidopa and levodopa tablets: Body as a Whole: chest pain, asthenia. Cardiovascular: cardiac irregularities, hypotension, orthostatic effects including orthostatic hypotension, hypertension, syncope, phlebitis, palpitation.
Gastrointestinal: dark saliva, gastrointestinal bleeding, development of duodenal ulcer, anorexia, vomiting, diarrhea, constipation, dyspepsia, dry mouth, taste alterations. Hematologic: agranulocytosis, hemolytic and non-hemolytic anemia, thrombocytopenia, leukopenia. Hypersensitivity: angioedema, urticaria, pruritus, Henoch-Schonlein purpura, bullous lesions (including pemphigus-like reactions).
Musculoskeletal: back pain, shoulder pain, muscle cramps. Nervous System/Psychiatric: psychotic episodes including delusions, hallucinations, and paranoid ideation, bradykinetic episodes ("on-off" phenomenon), confusion, agitation, dizziness, somnolence, dream abnormalities including nightmares, insomnia, paresthesia, headache, depression with or without development of suicidal tendencies, dementia, pathological gambling, increased libido including hypersexuality, impulse control symptoms. Convulsions also have occurred; however, a causal relationship with carbidopa and levodopa tablets has not been established.
Respiratory: dyspnea, upper respiratory infection. Skin: rash, increased sweating, alopecia, dark sweat. Urogenital: urinary tract infection, urinary frequency, dark urine.
Laboratory Tests: decreased hemoglobin and hematocrit; abnormalities in alkaline phosphatase, SGOT (AST), SGPT (ALT), LDH, bilirubin, BUN, Coombs test; elevated serum glucose; white blood cells, bacteria, and blood in the urine. Other adverse reactions that have been reported with levodopa alone and with various carbidopa and levodopa formulations, and may occur with carbidopa and levodopa tablets are: Body as a Whole: abdominal pain and distress, fatigue. Cardiovascular: myocardial infarction.
Gastrointestinal: gastrointestinal pain, dysphagia, sialorrhea, flatulence, bruxism, burning sensation of the tongue, heartburn, hiccups. Metabolic: edema, weight gain, weight loss. Musculoskeletal: leg pain.
Nervous System/Psychiatric: ataxia, extrapyramidal disorder, falling, anxiety, gait abnormalities, nervousness, decreased mental acuity, memory impairment, disorientation, euphoria, blepharospasm (which may be taken as an early sign of excess dosage; consideration of dosage reduction may be made at this time), trismus, increased tremor, numbness, muscle twitching, activation of latent Horner's syndrome, peripheral neuropathy. Respiratory: pharyngeal pain, cough. Skin: malignant melanoma, flushing.
Special Senses: oculogyric crises, diplopia, blurred vision, dilated pupils. Urogenital: urinary retention, urinary incontinence, priapism. Miscellaneous: bizarre breathing patterns, faintness, hoarseness, malaise, hot flashes, sense of stimulation.
Laboratory Tests: decreased white blood cell count and serum potassium; increased serum creatinine and uric acid; protein and glucose in urine.
🔄 Drug Interactions ▾
Drug Interactions Caution should be exercised when the following drugs are administered concomitantly with carbidopa and levodopa tablets. Symptomatic postural hypotension occurred when carbidopa and levodopa was added to the treatment of a patient receiving antihypertensive drugs. Therefore, when therapy with carbidopa and levodopa is started, dosage adjustment of the antihypertensive drug may be required.
For patients receiving MAO inhibitors (Type A or B), see CONTRAINDICATIONS. Concomitant therapy with selegiline and carbidopa and levodopa may be associated with severe orthostatic hypotension not attributable to carbidopa and levodopa alone (see CONTRAINDICATIONS). There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use of tricyclic antidepressants and carbidopa and levodopa.
Dopamine D 2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone) and isoniazid may reduce the therapeutic effects of levodopa. In addition, the beneficial effects of levodopa in Parkinson's disease have been reported to be reversed by phenytoin and papaverine. Patients taking these drugs with carbidopa and levodopa should be carefully observed for loss of therapeutic response.
Use of carbidopa and levodopa tablets, USP with dopamine-depleting agents (e.g., reserpine and tetrabenazine) or other drugs known to deplete monoamine stores is not recommended. Carbidopa and levodopa tablets, USP and iron salts or multivitamins containing iron salts should be coadministered with caution. Iron salts can form chelates with levodopa and carbidopa and consequently reduce the bioavailability of carbidopa and levodopa.
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.
🤰 Pregnancy ▾
Pregnancy No teratogenic effects were observed in a study in mice receiving up to 20 times the maximum recommended human dose of carbidopa and levodopa tablets. There was a decrease in the number of live pups delivered by rats receiving approximately two times the maximum recommended human dose of carbidopa and approximately five times the maximum recommended human dose of levodopa during organogenesis. Carbidopa and levodopa tablets caused both visceral and skeletal malformations in rabbits at all doses and ratios of carbidopa/levodopa tested, which ranged from 10 times/5 times the maximum recommended human dose of carbidopa/levodopa to 20 times/10 times the maximum recommended human dose of carbidopa/levodopa.
There are no adequate or well-controlled studies in pregnant women. It has been reported from individual cases that levodopa crosses the human placental barrier, enters the fetus, and is metabolized. Carbidopa concentrations in fetal tissue appeared to be minimal.
Use of carbidopa and levodopa tablets in women of childbearing potential requires that the anticipated benefits of the drug be weighed against possible hazards to mother and child.
🧒 Pediatric Use ▾
Pediatric Use Safety and effectiveness in pediatric patients have not been established. Use of the drug in patients below the age of 18 is not recommended.
🧓 Geriatric Use ▾
Geriatric Use In the clinical efficacy trials for carbidopa and levodopa tablets, USP, almost half of the patients were older than 65, but few were older than 75. No overall meaningful differences in safety or effectiveness were observed between these subjects and younger subjects, but greater sensitivity of some older individuals to adverse drug reactions such as hallucinations cannot be ruled out. There is no specific dosing recommendation based upon clinical pharmacology data as carbidopa and levodopa tablets, USP is titrated as tolerated for clinical effect.
🆘 Overdosage ▾
OVERDOSAGE Management of acute overdosage with carbidopa and levodopa tablets is the same as management of acute overdosage with levodopa. Pyridoxine is not effective in reversing the actions of carbidopa and levodopa tablets. General supportive measures should be employed, along with immediate gastric lavage.
Intravenous fluids should be administered judiciously and an adequate airway maintained. Electrocardiographic monitoring should be instituted and the patient carefully observed for the development of arrhythmias; if required, appropriate antiarrhythmic therapy should be given. The possibility that the patient may have taken other drugs as well as carbidopa and levodopa tablets should be taken into consideration.
To date, no experience has been reported with dialysis; hence, its value in overdosage is not known. Based on studies in which high doses of levodopa and/or carbidopa were administered, a significant proportion of rats and mice given single oral doses of levodopa of approximately 1,500 to 2,000 mg/kg are expected to die. A significant proportion of infant rats of both sexes are expected to die at a dose of 800 mg/kg.
A significant proportion of rats are expected to die after treatment with similar doses of carbidopa. The addition of carbidopa in a 1:10 ratio with levodopa increases the dose at which a significant proportion of mice are expected to die to 3,360 mg/kg.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY Mechanism of Action Parkinson's disease is a progressive, neurodegenerative disorder of the extrapyramidal nervous system affecting the mobility and control of the skeletal muscular system. Its characteristic features include resting tremor, rigidity, and bradykinetic movements. Symptomatic treatments, such as levodopa therapies, may permit the patient better mobility.
Current evidence indicates that symptoms of Parkinson's disease are related to depletion of dopamine in the corpus striatum. Administration of dopamine is ineffective in the treatment of Parkinson's disease apparently because it does not cross the blood-brain barrier. However, levodopa, the metabolic precursor of dopamine, does cross the blood-brain barrier, and presumably is converted to dopamine in the brain.
This is thought to be the mechanism whereby levodopa relieves symptoms of Parkinson's disease. Pharmacodynamics When levodopa is administered orally, it is rapidly decarboxylated to dopamine in extracerebral tissues so that only a small portion of a given dose is transported unchanged to the central nervous system. For this reason, large doses of levodopa are required for adequate therapeutic effect, and these may often be accompanied by nausea and other adverse reactions, some of which are attributable to dopamine formed in extracerebral tissues.
Since levodopa competes with certain amino acids for transport across the gut wall, the absorption of levodopa may be impaired in some patients on a high protein diet. Carbidopa inhibits decarboxylation of peripheral levodopa. It does not cross the blood-brain barrier and does not affect the metabolism of levodopa within the central nervous system.
The incidence of levodopa-induced nausea and vomiting is less with carbidopa and levodopa tablets than with levodopa. In many patients, this reduction in nausea and vomiting will permit more rapid dosage titration. Since its decarboxylase inhibiting activity is limited to extracerebral tissues, administration of carbidopa with levodopa makes more levodopa available for transport to the brain.
Pharmacokinetics Carbidopa reduces the amount of levodopa required to produce a given response by about 75% and, when administered with levodopa, increases both plasma levels and the plasma half-life of levodopa, and decreases plasma and urinary dopamine and homovanillic acid. The plasma half-life of levodopa is about 50 minutes, without carbidopa. When carbidopa and levodopa are administered together, the half-life of levodopa is increased to about 1.5 hours.
At steady state, the bioavailability of carbidopa from carbidopa and levodopa tablets is approximately 99% relative to the concomitant administration of carbidopa and levodopa. In clinical pharmacologic studies, simultaneous administration of carbidopa and levodopa produced greater urinary excretion of levodopa in proportion to the excretion of dopamine than administration of the two drugs at separate times. Pyridoxine hydrochloride (vitamin B 6 ), in oral doses of 10 mg to 25 mg, may reverse the effects of levodopa by increasing the rate of aromatic amino acid decarboxylation.
Carbidopa inhibits this action of pyridoxine; therefore, carbidopa and levodopa tablets can be given to patients receiving supplemental pyridoxine (vitamin B 6 ). Special Populations Geriatric: A study in eight young healthy subjects (21 to 22 yr) and eight elderly healthy subjects (69 to 76 yr) showed that the absolute bioavailability of levodopa was similar between young and elderly subjects following oral administration of levodopa and carbidopa. However, the systemic exposure (AUC) of levodopa was increased by 55% in elderly subjects compared to young subjects.
Based on another study in forty patients with Parkinson’s disease, there was a correlation between age of patients and the increase of AUC of levodopa following administration of levodopa and an inhibitor of peripheral dopa decarboxylase. AUC of levodopa was increased…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED Carbidopa and levodopa tablets, USP 25 mg/100 mg are mottled (orange colored speckles) yellow to light yellow colored oval shaped, biconvex, uncoated tablets debossed with "518" on one side and plain on the other side. They are supplied as follows: Bottle of 30 with child-resistant closure, NDC 62756-518-83 Bottle of 100 with child-resistant closure, NDC 62756-518-88 Bottle of 100, NDC 62756-518-08 Bottle of 500, NDC 62756-518-13 Bottle of 1000, NDC 62756-518-18 Carbidopa and levodopa tablets, USP 10 mg/100 mg are mottled blue to light blue colored oval shaped, biconvex, uncoated tablets debossed with "517" on one side and plain on the other side.
They are supplied as follows: Bottle of 30 with child-resistant closure, NDC 62756-517-83 Bottle of 100 with child-resistant closure, NDC 62756-517-88 Bottle of 100, NDC 62756-517-08 Bottle of 500, NDC 62756-517-13 Bottle of 1000, NDC 62756-517-18 Carbidopa and levodopa tablets, USP 25 mg/250 mg are mottled blue to light blue colored oval shaped, biconvex, uncoated tablets debossed with "519" on one side and plain on the other side. They are supplied as follows: Bottle of 30 with child-resistant closure, NDC 62756-519-83 Bottle of 100 with child-resistant closure, NDC 62756-519-88 Bottle of 100, NDC 62756-519-08 Bottle of 500, NDC 62756-519-13 Bottle of 1000, NDC 62756-519-18 Carbidopa and levodopa tablets, USP 25 mg/250 mg are mottled blue to light blue colored round shaped, biconvex, uncoated tablets debossed with "519" on one side and plain on the other side.
They are supplied as follows: Bottle of 100 with child-resistant closure, NDC 62756-985-01 Bottle of 500, NDC 62756-985-02 Storage Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Store in a tightly closed container, protected from light and moisture. Dispense in a tightly closed, light-resistant container.
📋 Description ▾
DESCRIPTION Carbidopa and levodopa tablet, USP is a combination of carbidopa and levodopa for the treatment of Parkinson’s disease and syndrome. Carbidopa USP, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.24. It is designated chemically as (-)-L-α-hydrazino-α-methyl-β-(3,4-dihydroxybenzene) propanoic acid monohydrate.
Its molecular formula is C 10 H 14 N 2 O 4 •H 2 O and its structural formula is: Tablet content is expressed in terms of anhydrous carbidopa which has a molecular weight of 226.23. Levodopa USP, an aromatic amino acid, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 197.2. It is designated chemically as (-)-L-α-amino-β-(3,4-dihydroxybenzene) propanoic acid.
Its molecular formula is C 9 H 11 NO 4 and its structural formula is: Carbidopa and levodopa is supplied as tablets in three strengths: Carbidopa and levodopa tablets, USP, 25 mg/100 mg, containing 25 mg of carbidopa and 100 mg of levodopa. Carbidopa and levodopa tablets, USP, 10 mg/100 mg, containing 10 mg of carbidopa and 100 mg of levodopa. Carbidopa and levodopa tablets, USP, 25 mg/250 mg, containing 25 mg of carbidopa and 250 mg of levodopa.
Inactive ingredients are microcrystalline cellulose, corn starch, pregelatinized maize starch, sodium starch glycolate, magnesium stearate. Carbidopa and levodopa tablets, USP 10 mg/100 mg and 25 mg/250 mg also contain FD&C Blue 2. Carbidopa and levodopa tablets, USP 25 mg/100 mg also contain D&C Yellow 10 and FD&C Yellow 6.
FDA approved dissolution method differs from that of the USP. cdld-structure-carbidopa cdld-structure-levodopa
💬 Information for Patients ▾
Information for Patients The patient should be informed that carbidopa and levodopa tablet is an immediate-release formulation of carbidopa and levodopa that is designed to begin release of ingredients within 30 minutes. It is important that carbidopa and levodopa tablets be taken at regular intervals according to the schedule outlined by the physician. The patient should be cautioned not to change the prescribed dosage regimen and not to add any additional antiparkinson medications, including other carbidopa and levodopa preparations, without first consulting the physician.
Patients should be advised that sometimes a 'wearing-off' effect may occur at the end of the dosing interval. The physician should be notified if such response poses a problem to lifestyle. Patients should be advised that occasionally, dark color (red, brown, or black) may appear in saliva, urine, or sweat after ingestion of carbidopa and levodopa tablets.
Although the color appears to be clinically insignificant, garments may become discolored. The patient should be advised that a change in diet to foods that are high in protein may delay the absorption of levodopa and may reduce the amount taken up in the circulation. Excessive acidity also delays stomach emptying, thus delaying the absorption of levodopa.
Iron salts (such as in multivitamin tablets) may also reduce the amount of levodopa available to the body. The above factors may reduce the clinical effectiveness of the levodopa or carbidopa and levodopa therapy. Patients should be alerted to the possibility of sudden onset of sleep during daily activities, in some cases without awareness or warning signs, when they are taking dopaminergic agents, including levodopa.
Patients should be advised to exercise caution while driving or operating machinery and that if they have experienced somnolence and/or sudden sleep onset, they must refrain from these activities. (See WARNINGS, Falling Asleep During Activities of Daily Living and Somnolence) There have been reports of patients experiencing intense urges to gamble, increased sexual urges, and other intense urges, and the inability to control these urges while taking one or more of the medications that increase central dopaminergic tone and that are generally used for the treatment of Parkinson’s disease, including carbidopa and levodopa tablets.
Although it is not proven that the medications caused these events, these urges were reported to have stopped in some cases when the dose was reduced or the medication was stopped. Prescribers should ask patients about the development of new or increased gambling urges, sexual urges or other urges while being treated with carbidopa and levodopa tablets. Patients should inform their physician if they experience new or increased gambling urges, increased sexual urges, or other intense urges while taking carbidopa and levodopa tablets.
Physicians should consider dose reduction or stopping the medication if a patient develops such urges while taking carbidopa and levodopa tablets. (See PRECAUTIONS, Impulse Control / Compulsive Behaviors)