The pharmacological therapeutic management of levodopa-induced dyskinesias in patients with Parkinson's disease.

The clinical management of levodopa-induced dyskinesia is difficult. Once present, dyskinesias are only partially improved by lowering the daily dose of levodopa and co-administering a D2 dopamine agonist. Therefore it appears to be necessary to use an NMDA-antagonist, such as amantadine, as an antidyskinetic agent. Clozapine may also improve dyskinesia without worsening akinesia, but it requires strict haematological monitoring. A long-term continuous subcutaneous infusion of apomorphine significantly reduces the dose of levodopa required, thereby markedly reducing dyskinesia, but this is difficult from a practical point of view. If none of these pharmacological strategies is successful, surgery should then be considered. Since the management of established levodopa-induced dyskinesia is difficult and often disappointing, efforts should be encouraged to try to prevent the occurrence of dyskinesia, before levodopa priming. This seems to be best achieved by the use of D2 dopamine agonists in the early stages of the disease, before, or in combination with, levodopa.