PROVIDED ARE AN AGENT FOR THE TREATMENT AND/OR PROPHYLAXIS OF A MOVEMENT DISORDER, THE AGENT FOR THE TREATMENT AND/OR PROPHYLAXIS WHEREIN THE MOVEMENT DISORDER IS EXTRAPYRAMIDAL SYNDROME, THE AGENT FOR THE TREATMENT AND/OR PROPHYLAXIS WHEREIN THE MOVEMENT DISORDER IS BRADYKINESIA, GAIT DISTURBANCE, DYSTONIA, DYSKINESIA OR TARDIVE DYSKINESIA, THE AGENT FOR THE TREATMENT AND/OR PROPHYLAXIS WHEREIN THE MOVEMENT DISORDER IS A SIDE EFFECT OF L-DOPA AND/OR DOPAMINE AGONIST THERAPY, AND THE LIKE, EACH CONTAINING A THIAZOLE DERIVATIVE REPRESENTED BY THE FORMULA (I) WHEREIN R¹ REPRESENTS ARYL AND THE LIKE, AND R² REPRESENTS PYRIDYL OR THE LIKE, OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF AS AN ACTIVE INGREDIENT.
