Continuous Delivery of Levodopa May Decrease Motor Complications of OFF Time

A small open-label study, published in the journal Movement Disorders, compared the efficacy and pharmacokinetics of continuously administered oral levodopa/carbidopa (sips administered at 5- to 10-minute intervals) for treatment of Parkinson's disease (PD) vs the current standard treatment taken once or twice per day for treatment. In this study, 18 patients with PD took the continuous dose for 8 hours or their usual dose alternating between the 2 treatments every other day. Patients had 43% less mean OFF time when they took the continuous treatment than when they took the standard treatment (P <.001).

During each 8-hour study period, blood samples were drawn between 4 and 8 hours when patients were in a relatively steady state. Blood samples drawn when patients were using the continuous dosing had less variability in plasma levodopa concentration compared with when they took their standard dose. The fluctuation index was 0.99 ± 0.09 for continuous treatment vs 1.38 ± 0.12 for standard dosing and the coefficient of variation was 0.35 ± 0.03 vs. 0.49 ± 0.04, respectively (P <.001 for both measures).