Levodopa-Carbidopa Intestinal Gel in Patients with Parkinson's Disease: A Systematic Review

Levodopa-carbidopa intestinal gel (LCIG) is available in several countries for the treatment of advanced levodopa-responsive Parkinson's disease (PD) with severe motor fluctuations and dyskinesia when other treatments have not given satisfactory results.

Our objective was to summarize the present evidence base for LCIG therapy through a systematic review of the literature.

Studies were identified from the PubMed and EMBASE databases up to 12 March 2016 using the following search terms: Parkinson disease, duodopa, levodopa/carbidopa intestinal gel, levodopa-carbidopa intestinal gel, LCIG, l-dopa infusion, levodopa infusion, duodenal l-dopa infusion, and duodenal levodopa infusion. Data extraction focused on whether LCIG therapy improves motor and non-motor outcomes as well as quality of life in PD patients compared with conventional therapy, apomorphine infusion, or deep brain stimulation. Randomized controlled trials (RCTs) and observational studies, with or without a control group, that included more than ten patients were included. The search was limited to peer-reviewed articles published in full in the English language and involving humans.

Infusion of LCIG reduced "off" time, increased "on" time without increasing troublesome dyskinesias, and improved quality of life in three RCTs (one double-blind). Open-label follow-ups confirm these findings. The data evaluating long-term efficacy and safety are still limited.

The quality of evidence that LCIG is effective in reducing fluctuating motor symptoms and improving quality of life is moderate. Quality of evidence for reduction of non-motor symptoms is very low. Safety issues mainly relate to the intestinal infusion system. LCIG might be a useful treatment option in PD patients with severe motor fluctuations.