On-demand treatments for advanced Parkinson’s disease
Peter A. LeWitt MD, MMedSc
Wayne State University School of Medicine, Detroit Michigan 48201 USA
With chronic orally administered levodopa therapy, some Parkinson’s disease (PD) patients experience irregular symptomatic control [1, 2]. In this situation, a means for rapid and reliable reversal of “off” states is commonly needed. Two novel treatments for achieving this goal were recently introduced in the U.S., joining subcutaneously administered apomorphine. Each of these on-demand PD medications utilizes routes of drug delivery differing from orally administered levodopa, which requires absorption in the proximal portion of the small intestine . Levodopa uptake can be capricious, and the clinical consequences have not been solved by sustained-release levodopa formulations, continuous enteral infusion, drugs for extending duration of each levodopa dose (COMT and MAO-B inhibitors), long-acting dopaminergic compounds, or adenosine A2a antagonism. The new on-demand therapies for PD are apomorphine imbedded in strips for drug uptake through the sublingual oral mucosa and an inhaled micro-powder formulation of levodopa for pulmonary absorption. This lecture will review the development of the marketed on-demand products and will compare their performance attributes.
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