Early treatment of Parkinson's disease: opportunities for managed care.

The diagnosis and treatment of Parkinson's disease (PD) typically occur when the disease has already progressed to a relatively advanced stage in which motor symptoms are clearly evident and substantial neurophysiological damage has already taken place. Nonmotor symptoms, which account for a large proportion of PD symptoms, usually emerge much earlier and offer both an early indication for treatment and a therapeutic target. A growing body of data from the medical literature points to several critical advantages that may be associated with early therapeutic intervention in PD. The most evident benefit of early intervention is a reduction in symptoms, particularly dyskinesia, and the delay of levodopa initiation. Clinical trials suggest but have yet to conclusively demonstrate that early treatment can slow disease progression. Both the diminishment of symptoms and the potential for slowing disease progression have large implications for improving patient quality of life. The enormous direct costs associated with PD would also likely be reduced over the long term with earlier treatment. The great majority of costs attributable to PD occur when the disease is at its most advanced stage and when symptoms are most severe. An early-treatment strategy that diminishes symptoms and that has the potential to slow disease progression could have a meaningful impact on PD expenditures. Adherence, too, must be taken into consideration, particularly since PD patients are generally poorly adherent to prescribed therapies, especially therapies with complex dosing schedules. Taking advantage of more convenient and adherencefriendly drug formulations may further help to improve outcomes and lower costs in PD.