ArticleBrain and behavior2017
Effects of levodopa/carbidopa intestinal gel versus oral levodopa/carbidopa on B vitamin levels and neuropathy.
Article in Brain and behavior, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 32 papers, 5 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
32 citing papers in PubMed, 5 syntheses or guidelines pooled it, 53 citations in OpenAlex.
- Invasive therapies for Parkinson's disease: an adapted excerpt from the guidelines of the German Society of Neurology.Journal of neurology · 2025Pooled it
- Pooled it
- How to Optimize the Effectiveness and Safety of Parkinson's Disease Therapy? - A Systematic Review of Drugs Interactions with Food and Dietary Supplements.Current neuropharmacology · 2022Pooled it
- Dietary Approaches to Improve Efficacy and Control Side Effects of Levodopa Therapy in Parkinson's Disease: A Systematic Review.Advances in nutrition (Bethesda, Md.) · 2021Pooled it
- The Long-Term Impact of Levodopa/Carbidopa Intestinal Gel on 'Off'-time in Patients with Advanced Parkinson's Disease: A Systematic Review.Advances in therapy · 2021Pooled it
- Do We Need to Monitor B-Vitamins and Homocysteine During Initiation of Foslevodopa/Foscarbidopa Therapy?Movement disorders : official journal of the Movement Disorder Society · 2026Article
- Review
- Polyneuropathy in Parkinson's disease and atypical Parkinsonian syndromes: clinical impact and risk factors.Journal of neural transmission (Vienna, Austria : 1996) · 2026Article
- Reply to the Letter on: "Electrophysiological and Biochemical Evaluations of Neuropathy Risk in Oral Levodopa versus Levodopa/Carbidopa Intestinal Gel Treatment".Arquivos de neuro-psiquiatria · 2026Article
- Comment on "Electrophysiological and Biochemical Evaluations of Neuropathy Risk in Oral Levodopa versus Levodopa/Carbidopa Intestinal Gel Treatment".Arquivos de neuro-psiquiatria · 2026Article
- Biochemical and nutritional changes during continuous subcutaneous apomorphine infusion in advanced Parkinson's disease: findings from an observational cohort.Therapeutic advances in neurological disorders · 2026Article
- Electrophysiological and biochemical evaluations of neuropathy risk in oral levodopa versus levodopa/carbidopa intestinal gel treatment.Arquivos de neuro-psiquiatria · 2025Article
- Parkinson's disease is characterized by vitamin B6-dependent inflammatory kynurenine pathway dysfunction.NPJ Parkinson's disease · 2025Article
- Oral Levodopa Therapy, Vitamin B6 and Peripheral Neuropathy: A Cross-Sectional Observational Study.Movement disorders clinical practice · 2025Article
- Parkinson's disease and vitamins: a focus on vitamin B12.Journal of neural transmission (Vienna, Austria : 1996) · 2024Review
- Large-fiber neuropathy in Parkinson's disease: a narrative review.Neurological research and practice · 2024Review
- Decreased hepatic enzymes reflect the decreased vitamin B6 levels in Parkinson's disease patients.Pharmacology research & perspectives · 2024Article
- Homocysteine, vitamin B metabolites, dopamine-substituting compounds, and symptomatology in Parkinson's disease: clinical and therapeutic considerations.Journal of neural transmission (Vienna, Austria : 1996) · 2023Review
- Should continuous dopaminergic stimulation be a standard of care in advanced Parkinson's disease?Journal of neural transmission (Vienna, Austria : 1996) · 2023Review
- Clinical benefit of MAO-B and COMT inhibition in Parkinson's disease: practical considerations.Journal of neural transmission (Vienna, Austria : 1996) · 2023Review
Corrections and comments
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Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo determine the possible interactions between levodopa therapy and plasma levels of B vitamins in patients with advanced idiopathic Parkinson's disease (IPD) in the context of either oral levodopa therapy or levodopa/carbidopa intestinal gel (LCIG). Secondly, to determine the prevalence of neuropathy and its relation to plasma levels of B vitamins and homocysteine.
methodsMedication doses, neurographies, and serum levels of pyridoxine, cobalamin, folate, and homocysteine of eight LCIG and 13 orally treated advanced IPD patients matched for age, Hoehn & Yahr stage, and UPRDS III were collected. This data was analyzed for correlation with daily levodopa dose (LDD).
resultsLICG patients had a longer disease duration and higher LDD. All LCIG patients and most orally treated patients had sensorimotor axonal polyneuropathy. Of all plasma vitamin levels, pyridoxine was decreased most and significantly lower in the LCIG group. Cobalamin and folate, however, were within the lower reference range, and homocysteine highly elevated, all without any significant difference between both groups. LDD correlated significantly with pyridoxine deficiency (
conclusionsPyridoxine deficiency and hyperhomocysteinemia are dependent on the daily levodopa/carbidopa dose, while levels of cobalamin and folate are not. The mode of application of levodopa/carbidopa has no impact on B-vitamin levels. Neuropathy is very frequent in advanced IPD; however, it remains to be investigated further whether neuropathy is more frequent in LCIG than in orally levodopa/carbidopa-treated advanced IPD patients.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.