Fluctuations in plasma levodopa and motor responses with liquid and tablet levodopa/carbidopa

Authors

  • L. Verhagen Metman,

    1. Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A.
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  • J. Hoff,

    1. Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A.
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  • M. M. Mouradian,

    1. Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A.
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  • Dr. T. N. Chase

    Corresponding author
    1. Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A.
    • National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 10, Room 5C103, Bethesda, MD 20892, U.S.A.
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Abstract

To evaluate the ability of orally administered liquid levodopa/carbidopa (LD/CD) to stabilize plasma levodopa levels and reduce motor reponse fluctuations in Parkinson's disease, five patients received LD/CD hourly, as standard tablets or as an aqueous solution on two separate days in a double-blind, placebo-controlled, cross-over design. Except for a slightly earlier peak plasma levodopa level, no significant advantage of the liquid formulation over tablet therapy was found. However, liquid LD/CD could be helpful in quickly resolving “off” states and by facilitating small dose adjustments that are not possible with tablets.

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