Practice parameter: Initiation of treatment for Parkinson’s disease: An evidence-based review [RETIRED]

TLDR

The 1993 AAN Practice Parameter identified levodopa as the most effective treatment for Parkinson’s disease, but subsequent years have seen the introduction and study of new agents such as non‑ergot dopamine agonists and sustained‑release levodopa. This review seeks to reassess treatment of de novo Parkinson’s disease, addressing whether selegiline offers neuroprotection, which agent best initiates symptomatic therapy, and whether sustained‑release levodopa confers advantages over immediate‑release formulations. The authors performed a systematic literature review of human trials in de novo Parkinson’s disease from 1966 to 1999 using MEDLINE, EMBASE, and the Cochrane Library, including only class I or II evidence. The review concludes that selegiline provides only mild symptomatic benefit without neuroprotection, that either levodopa or a dopamine agonist can initiate therapy—with levodopa offering greater motor improvement but higher dyskinesia risk—and that sustained‑release levodopa offers no advantage over immediate‑release formulations.

Abstract

In 1993, the last AAN Practice Parameter on medical treatment of Parkinson's disease (PD) concluded that levodopa was the most effective drug for management of this disorder. Since then, a number of new compounds including non-ergot dopamine agonists (DA) and sustained-release levodopa have been released and studied. Thus, the issue of treatment in de novo PD patients warrants reexamination. Specific questions include: 1) does selegiline offer neuroprotection; 2) what is the best agent with which to initiate symptomatic treatment in de novo PD; and 3) is there a benefit of sustained release levodopa over immediate-release levodopa? Using evidence-based principles, a literature review using MEDLINE, EMBASE, and the Cochrane Library was performed to identify all human trials in de novo PD between 1966 and 1999. Only articles that fulfilled class I or class II evidence were included. Based on this review, the authors conclude: 1) Selegiline has very mild symptomatic benefit (level A, class II evidence) with no evidence for neuroprotective benefit (level U, class II evidence). 2) For PD patients requiring initiation of symptomatic therapy, either levodopa or a DA can be used (level A, class I and class II evidence). Levodopa provides superior motor benefit but is associated with a higher risk of dyskinesia. 3) No evidence was found that initiating treatment with sustained-release levodopa provides an advantage over immediate-release levodopa (level B, class II evidence).