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.