Safinamide for pain management in patients with Parkinson's disease.

INTRODUCTION: Pain is often neglected in Parkinson's disease (PD), although it impacts most PD patients. While the mechanism of pain in PD is still being studied, various pharmacological, interventional, and alternative treatment options have been offered for pain relief. Safinamide, a recently approved drug for PD, has shown promising results in improving pain in patients with PD. Several clinical studies report changes in pain scores in PD patients treated with safinamide, but these have not been systematically summarized. Therefore, our main goal was to perform a systematic review and statistical analysis of relevant studies.

METHODS: A systematic search of studies was conducted using four databases: Pubmed, Cochrane Library, Google Scholar, and Scopus. The nine included randomized controlled trials did not provide sufficient data for a meta-analysis; therefore, we conducted a qualitative systematic review.

RESULTS: Our results suggest that safinamide at a daily dose of 100mg is more effective for treating PD pain than that of 50mg. Moreover, the reduction in fluctuation-related pain and pain from edema was more consistent when treated with safinamide compared to other PD pain types. We also attempted to suggest a mechanism of action for safinamide on pain processing in the brain, which should be explored in more detail in future studies.

CONCLUSION: Clinical evidence suggests that safinamide may be particularly beneficial for PD patients experiencing fluctuation-related pain and pain from edema, as these subtypes of pain showed greater improvement compared to other types of pain. Based on the findings of the included studies, safinamide appears to relieve the overall pain burden. However, the lack of sufficient data for conducting a meta-analysis highlights the need for future studies to report mean pain scores and their standard deviations.