The present invention describes the use of a NK1-antagonist, in combination with 6-propylamino-4,5,6,7-tetrahydro-1,3-benzothiazole-2-amine, to facilitate the treatment of a patient suffering from a synucleinopathy by enabling a therapeutically effective 6-propylamino-4,5,6,7-tetrahydro-1,3-benzothiazole-2-amine daily dose to act without the typical adverse effects caused by pramipexole dihydrochloride monohydrate when administered alone.