Duodopa® treatment for advanced Parkinson's disease: a review of efficacy and safety.

Enterally administered levodopa/carbidopa gel (Duodopa®) is used for the treatment of advanced Parkinson's disease (PD) in patients with motor fluctuations and dyskinesias. This review summarizes the current efficacy and safety data on this drug. Clinically important differences (CID) have been used to assess whether statistical improvements in symptoms translate into meaningful improvements for the patients. A PubMed search in February 2012 found 23 papers with efficacy data and 33 with safety data. Of 11 studies reporting Unified Parkinson's Disease Rating Scale (UPDRS) III scores, 10 found improvements that met the CID of 10.8 points. Of 7 studies reporting UPDRS IV scores, 5 found improvements meeting the CID of 2.3 points. Quality of life (QoL) was assessed in 6 studies using the 8- or 39-question version of the Parkinson's disease Questionnaire, and all reported improvements meeting the CID (10 points). Due to the nature of the data, it is not possible to give exact numbers for the frequency of adverse events. However, the findings seem to be in line with a previous report stating the majority of adverse events were related to the infusion system or surgical procedure rather than the drug. In conclusion, the large majority of studies have reported that Duodopa® is clinically effective in relieving the symptoms of advanced PD and improving QoL in comparison with conventional therapy. High-quality randomized trials with larger patient numbers will yield greater insights into the efficacy and safety of this treatment.