Oral and infusion levodopa-based strategies for managing motor complications in patients with Parkinson's disease.

Levodopa is the most effective treatment for Parkinson's disease (PD) signs and symptoms, and patients invariably will require it during the course of the disease. It also provides benefits in activities of daily living, quality of life and life expectancy. However, after a few years of levodopa treatment the majority of patients will experience motor fluctuations and dyskinesia. Initial use of a dopamine receptor agonist may delay the emergence of motor fluctuations but at the cost of reduced symptomatic control compared with the use of levodopa in some cases. Adequate management of motor fluctuations and dyskinesia is essential to maintaining satisfactory quality of life at the advanced stage of disease. Various levodopa-based strategies are currently available that aim to control motor complications (wearing-off and dyskinesia) in PD and each approach has its own unique benefit and risk profile. Strategies such as dose fragmentation (smaller, more frequent dosing) or the use of orally administered, liquid levodopa formulations or melevodopa can reduce off-time intervals or facilitate absorption. More recently introduced, continuous delivery of dopaminergic medications may represent a more effective approach to treat motor complications in advanced PD and its effect can be perceived from improvement in clinical scales, as well as in health-related items. Indeed, continuous levodopa delivery by duodenal infusion may stabilize and significantly improve motor function as well as patients' quality of life. We propose a treatment algorithm that takes into account all currently available levodopa-based treatment strategies for motor complications in patients with PD.