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Carbidopa and Levodopa (Carbidopa / Levodopa) - Summary

 
 



SUMMARY

CARBIDOPA AND LEVODOPA TABLETS USP

Carbidopa and levodopa tablets are a combination of carbidopa and levodopa for the treatment of Parkinson’s disease and syndrome. Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound, slightly soluble in water.

Carbidopa and levodopa tablets are indicated in the treatment of the symptoms of idiopathic Parkinson's disease (paralysis agitans), post-encephalitic parkinsonism, and symptomatic parkinsonism which may follow injury to the nervous system by carbon monoxide intoxication and/or manganese intoxication. This product is indicated in these conditions to permit the administration of lower doses of levodopa with reduced nausea and vomiting, with more rapid dosage titration, with a somewhat smoother response, and with supplemental pyridoxine (vitamin B6).

In some patients a somewhat smoother antiparkinsonian effect results from therapy with carbidopa and levodopa than with levodopa. However, patients with markedly irregular ("on‑off") responses to levodopa have not been shown to benefit from carbidopa and levodopa therapy.

Although the administration of carbidopa permits control of parkinsonism and Parkinson's disease with much lower doses of levodopa, there is no conclusive evidence at present that this is beneficial other than in reducing nausea and vomiting, permitting more rapid titration, and providing a somewhat smoother response to levodopa.

Certain patients who responded poorly to levodopa have improved when carbidopa and levodopa was substituted. This is most likely due to decreased peripheral decarboxylation of levodopa which results from administration of carbidopa rather than to a primary effect of carbidopa on the nervous system. Carbidopa has not been shown to enhance the intrinsic efficacy of levodopa in parkinsonian syndromes.

In considering whether to give this combination product to patients already on levodopa who have nausea and/or vomiting, the practitioner should be aware that, while many patients may be expected to improve, some do not. Since one cannot predict which patients are likely to improve, this can only be determined by a trial of therapy. It should be further noted that in controlled trials comparing carbidopa and levodopa with levodopa, about half of the patients with nausea and/or vomiting on levodopa improved spontaneously despite being retained on the same dose of levodopa during the controlled portion of the trial.


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NEWS HIGHLIGHTS

Published Studies Related to Carbidopa and Levodopa (Carbidopa / Levodopa)

Are high doses of carbidopa a concern? A randomized, clinical trial in Parkinson's disease. [2012]
Recommended doses of carbidopa are 75-200 mg/day...

Comparison of orally dissolving carbidopa/levodopa (Parcopa) to conventional oral carbidopa/levodopa: A single-dose, double-blind, double-dummy, placebo-controlled, crossover trial. [2010.12.15]
Levodopa use in fluctuating Parkinson's disease (PD) is complicated by an inconsistent and prolonged onset to clinical improvement.This small pilot study did not show significant group differences favoring OD C/L; however, larger studies may be justified, and individual patients may benefit.

Night-time bioavailability of levodopa/carbidopa/entacapone is higher compared to controlled-release levodopa/carbidopa. [2010.11]
OBJECTIVE: Controlled-release levodopa/carbidopa (CR-LC) is often used to provide prolonged control of night-time motor symptoms in patients with Parkinson's disease (PD). Levodopa/carbidopa/entacapone (LCE) provides higher bioavailability of levodopa compared with levodopa/carbidopa formulations and has been shown to be effective in PD patients with wearing-off symptoms. The aim of this study was to compare the bioavailability of levodopa after a single evening dose (administered at 10 p.m.) of LCE 200 or CR-LC 200... CONCLUSIONS: The results of this study demonstrate that a single bedtime dose of LCE 200 provides higher bioavailability of levodopa compared to CR-LC 200.

Levodopa-carbidopa may improve vision loss in indirect traumatic optic neuropathy. [2010.10]
To compare the effect of levodopa-carbidopa on the visual outcome of patients with indirect traumatic optic neuropathy (ITON), this randomized, double-blind, placebo-controlled study was conducted on 32 patients with ITON within 6 days after trauma. Patients underwent a complete ocular examination, pattern visual evoked potential (PVEP) testing, and high-resolution orbital computed tomography (CT) scanning...

Initiating levodopa/carbidopa therapy with and without entacapone in early Parkinson disease: the STRIDE-PD study. [2010.07]
OBJECTIVE: L-dopa is the most widely used and most effective therapy for Parkinson disease (PD), but chronic treatment is associated with motor complications in the majority of patients. It has been hypothesized that providing more continuous delivery of L-dopa to the brain would reduce the risk of motor complications, and that this might be accomplished by combining L-dopa with entacapone, an inhibitor of catechol-O-methyltransferase, to extend its elimination half-life... INTERPRETATION: Initiating L-dopa therapy with LCE failed to delay the time of onset or reduce the frequency of dyskinesia compared to LC. In fact, LCE was associated with a shorter time to onset and increased frequency of dyskinesia compared to LC. These results may reflect that the treatment protocol employed did not provide continuous L-dopa availability and the higher L-dopa dose equivalents in the LCE group.

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Clinical Trials Related to Carbidopa and Levodopa (Carbidopa / Levodopa)

Bioequivalence Study of Carbidopa/Levodopa/Entacapone Combination vs. Carbidopa/Levodopa Combination Plus Entacapone in Healthy Volunteers [Completed]

Bioequivalence Study of Carbidopa/Levodopa/Entacapone Combination vs. Carbidopa/Levodopa Combination Plus Entacapone in Healthy Volunteers [Completed]

Bioequivalence Study of Carbidopa/Levodopa/Entacapone Combination vs. Carbidopa/Levodopa Combination Plus Entacapone in Healthy Volunteers [Completed]

Bioequivalence Study of Carbidopa/Levodopa/Entacapone Combination vs. Carbidopa/Levodopa Combination Plus Entacapone Under Fasting Conditions in Healthy Volunteers [Completed]

Efficacy of Levodopa/Carbidopa/Entacapone vs. Levodopa/Carbidopa in Parkinson's Disease Patients With Early Wearing Off [Active, not recruiting]
The study will evaluate the efficacy of levodopa/carbidopa/entacapone vs. levodopa/carbidopa in patients with Parkinson's disease and early wearing off with levodopa

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Reports of Suspected Carbidopa and Levodopa (Carbidopa / Levodopa) Side Effects

Dyskinesia (16)Hallucination, Visual (12)Tremor (10)Agitation (9)Confusional State (9)Fall (9)Gait Disturbance (9)Respiratory Disorder (6)Muscle Rigidity (6)Delirium (6)more >>


Page last updated: 2013-02-10

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