In April 2017, the U.S. FDA approved Xadago (safinamide) as an add-on treatment for individuals with PD who are currently taking levodopa and carbidopa. The tablet is taken once-daily, with or without food, and should be utilized when current medications are leading to “off” episodes. “Off” episodes are defined as periods of time in which breakthrough symptoms are occurring despite being on a full treatment regimen. These breakthrough symptoms can include tremor and difficulty walking, among other issues.
Safety and efficacy
The efficacy and safety of Xadago was analyzed in two clinical trials consisting of 645 and 549 individuals each. All participants had PD and were experiencing “off” episodes while taking levodopa. Both trials yielded similar results, with those receiving Xadago in addition to their levodopa experiencing more “on” time, and a greater reduction in PD symptoms. In the studies, this manifested as a reduction in dyskinesia (involuntary movements) and “off” episodes, as well as an increase in “on” time as compared to a placebo group. Additionally, an improvement in motor function during “on” time was found for those taking Xadago as opposed to placebo.
Xadago’s active ingredient is safinamide mesylate, and it is manufactured by Newron Pharmaceuticals. It is a monoamine oxidase type B (MAO-B) inhibitor, putting it in the same class as selegiline (Eldepryl, EMSAM, and Zelapar) and rasagiline (Azilect). The most common side effects reported while taking Xadago were falls, trouble sleeping or falling asleep, nausea, and uncontrolled, involuntary movements. More serious, though less common, adverse side effects included falling asleep during daily activities, psychotic behavior and hallucinations, serotonin syndrome, high blood pressure, fever, confusion, retinal pathology, and problems with impulse control or impulsive behaviors.
It is not known if Xadago is safe for use in children, nor if it is effective as a monotherapy (on its own without levodopa and carbidopa). Those with severe liver problems, or who are on cold medicines containing dextromethorphan should not take Xadago. Additionally, those taking St. John’s Wort, opioids, cyclobenzaprine, and certain antidepressants (such as SNRI’s, tricyclics, tetracyclics, and triazolopyridines) should not take Xadago, as a rare and potentially life-threatening condition called serotonin syndrome can occur. Finally, those on other MAOI medications (monoamine oxidase inhibitors) should not take Xadago as it can cause a severe increase in blood pressure.
U.S. Food & Drug Administration. FDA approves drug to treat Parkinson’s disease. Mar 21 2017. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm547852.htm.
Devito, Loren. FDA approves Xadago for Parkinson’s Disease. The Michael J. Fox Foundation for Parkinson’s Research. Mar 22 2017. https://www.michaeljfox.org/foundation/news-detail.php?fda-approves-xadago-for-parkinson-disease.