Levodopa is the most efficacious treatment in the management of Parkinson's 
disease. Unfortunately, chronic use of traditional levodopa/dopa decarboxylase 
inhibitor formulations is associated with the development of complications, such 
as wearing-off and dyskinesia. In an attempt to avoid these complications, some 
physicians delay the introduction of levodopa or employ levodopa-sparing 
strategies; however, these strategies are frequently suboptimal for patients. As 
most patients require the superior efficacy of levodopa during the course of 
their disease, an appreciation of the changing response to levodopa over time 
and an understanding of the pharmacokinetic principles underlying the 
development of complications such as wearing-off is essential in the long-term 
management of the patient.