Advances in levodopa therapy for Parkinson disease: Review of RYTARY (carbidopa and levodopa) clinical efficacy and safety.

Parkinson disease (PD) is a slowly progressive, incurable, neurodegenerative disorder with progressive motor symptoms that can be managed with treatments. Levodopa is generally recognized as the most effective and widely used treatment for PD. It improves function and quality of life, morbidity, and mortality, and therefore reduces individual and societal costs. Levodopa has a relatively short half-life, however, and is quickly metabolized in the plasma, leading to fluctuations, including wearing-off of effect and inconsistent symptomatic relief as well as development of dyskinesias, with both wearing off and dyskinesias worsening with advancing disease. Immediate-release and controlled-release formulations have been used with success, but motor fluctuations remain a problem. RYTARY (levodopa and carbidopa, IPX066) is an oral extended-release therapy composed of carbidopa-levodopa microbeads designed to dissolve at various rates that allows for quick absorption and sustained levodopa release over an extended period. In development studies, RYTARY improved symptoms in patients with both early and advanced PD and offered significantly improved Unified Parkinson Disease Rating Scale scores and "on" times, without worsening troublesome dyskinesias when compared to other levodopa formulations. Tolerability and safety were comparable to other formulations. This section reviews the data that support the use of RYTARY in the treatment of PD.