Other pharmacological treatments for motor complications and dyskinesias

Controlling motor complications becomes increasingly difficult with disease progression. The "wearing-off" phenomenon is the most-common motor fluctuation. Wearing-off can be treated by dietary manipulation, shortening the dosing interval, substituting sustained-release levodopa, adding amantadine, or monoamine oxidase type B inhibitors, and other options, including catechol-O-methyltransferase inhibitors and the approved dopamine agonists addressed in another chapter. The rotigotine constant-delivery system is being developed to treat wearing-off symptoms. Istradefylline (KW-6002), an adenosine A(2A) receptor antagonist, has been studied for wearing-off and the results will be discussed. The on-off fluctuations can be treated with liquid levodopa and the rescue therapy of injectable apomorphine. Patients may also suffer from dyskinesias. Dyskinesias can be treated with small doses of liquefied levodopa-carbidopa, amantadine, and clozapine, an atypical neuroleptic.