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Lodosyn (Carbidopa) - Summary

 
 



LODOSYN SUMMARY

TABLETS
LODOSYN®
(CARBIDOPA)

Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.

LODOSYN is indicated for use with SINEMET (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.

LODOSYN is for use with SINEMET (Carbidopa-Levodopa) in patients for whom the dosage of SINEMET (Carbidopa-Levodopa) provides less than adequate daily dosage (usually 70 mg daily) of carbidopa.

LODOSYN is for use with levodopa in the occasional patient whose dosage requirement of carbidopa and levodopa necessitates separate titration of each entity.

LODOSYN is used with SINEMET (Carbidopa-Levodopa) or with levodopa to permit the administration of lower doses of levodopa with reduced nausea and vomiting, more rapid dosage titration, and with a somewhat smoother response. However, patients with markedly irregular (“on-off”) responses to levodopa have not been shown to benefit from the addition of carbidopa.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, supplemental pyridoxine (vitamin B6), can be given to patients when they are receiving carbidopa and levodopa concomitantly or as SINEMET (Carbidopa-Levodopa).

Although the administration of LODOSYN 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 alone have improved when carbidopa and levodopa were given concurrently. This was most likely due to decreased peripheral decarboxylation of levodopa rather than to a primary effect of carbidopa on the peripheral nervous system. Carbidopa has not been shown to enhance the intrinsic efficacy of levodopa.

In considering whether to give LODOSYN with SINEMET (Carbidopa-Levodopa) or with levodopa to patients who have nausea and/or vomiting, the physician should be aware that, while many patients may be expected to improve, some may 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 alone, about half the patients with nausea and/or vomiting on levodopa alone improved spontaneously despite being retained on the same dose of levodopa during the controlled portion of the trial.


See all Lodosyn indications & dosage >>

NEWS HIGHLIGHTS

Published Studies Related to Lodosyn (Carbidopa)

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...

Effects of carbidopa and entacapone on the metabolic fate of the norepinephrine prodrug L-DOPS. [2011.01]
BACKGROUND: L-threo-3,4-dihydroxyphenylserine (L-DOPS), a norepinephrine (NE) prodrug, is investigational for orthostatic hypotension, which occurs commonly in Parkinson's disease. Adjunctive anti-parkinsonian drugs might interact with L-DOPS. We tested whether L-aromatic amino-acid decarboxylase inhibition by carbidopa (CAR) attenuates L-DOPS conversion to NE and blocks the pressor effect of L-DOPS, whereas catechol-O-methyltransferase inhibition by entacapone (ENT) interferes with L-DOPS metabolism and augments the pressor effect... CONCLUSIONS: After L-DOPS administration plasma, NE levels do not increase sufficiently to increase blood pressure. Pressor responses to L-DOPS seem to reflect NE produced extraneuronally that escapes extensive enzymatic deamination and O-methylation and evokes vasoconstriction before reaching the systemic circulation.

Effects of carbidopa and entacapone on the metabolic fate of the norepinephrine prodrug L-DOPS. [2011]
interferes with L-DOPS metabolism and augments the pressor effect... CONCLUSIONS: After L-DOPS administration plasma, NE levels do not increase

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.

more studies >>

Clinical Trials Related to Lodosyn (Carbidopa)

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]

Study of Efficacy, Safety and Tolerability of Levodopa-Carbidopa Intestinal Gel in Levodopa-Responsive Parkinson's Subjects [Recruiting]

The primary objective of this study will be to demonstrate the superiority of levodopa -

carbidopa intestinal gel over treatment with optimized oral levodopa/carbidopa during 12 weeks. The study duration is 4 months.

more trials >>


Page last updated: 2013-02-10

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