METHOD AND COMPOSITION TO INDIVIDUALIZE LEVODOPA/CARBIDOPA THERAPY USING A BREATH TEST

摘要

The present invention relates, generally to a method of determining and assessing L-3,4-dihydroxyphenylalanine (a.k.a., Levodopa; L-dopa; or LD) metabolic capacity in an individual mammalian subject via a breath assay, by determining the relative amount of¹³CO₂ exhaled by the subject upon intravenous or oral administration of a ¹³C-labeled substrate, such as levodopa. The present invention is useful as an in vivo phenotype assay for individualizing LD/ Carbidopa(CD) therapy in Parkinsons disease patients by optimizing the dose and timing of the dose of dopamine decarboxylase (DDC) inhibitor like CD for systemic suppression of dopamine metabolism .by evaluating DDC enzyme activity using the metabolite ¹³CO₂ in expired breath.