Early versus delayed initiation of entacapone in levodopa-treated patients with Parkinson's disease: a long-term, retrospective analysis.

Background: We analysed data from three clinical trials in Parkinson's disease (PD) patients with wearing-off to determine whether early enhancement of levodopa therapy with entacapone can lead to better long-term outcomes than delayed entacapone treatment.

Methods: Post-hoc analysis of pooled data from three randomized, double-blind, placebo-controlled studies and their long-term, open-label extension phases. In all three studies, patients on levodopa/dopa-decarboxylase inhibitor (DDCI) were first randomized to entacapone ('early-start' group) or placebo ('delayed-start' group) for the initial 6-month double-blind phase, after which all patients received open-label levodopa/DDCI and entacapone treatment for up to 5 years.

Results: A total of 488 PD patients with wearing-off were included in the analysis. A statistically significant benefit of early initiation of levodopa/DDCI and entacapone was found, with an improvement in Unified Parkinson's Disease Rating Scale Part III (motor) score of -1.66 (95% confidence intervals [-3.01, -0.31]) points compared with the delayed-start treatment group (P < 0.05). Levodopa/DDCI and entacapone therapy was well tolerated. There was no excess of dyskinesia in the early-start group.

Conclusions: These data suggest that early rather than delayed addition of entacapone to levodopa/DDCI in PD patients with wearing-off provides a modest clinical benefit over levodopa/DDCI that is maintained for up to 5 years.