Clinically used anti-PD drugs include dopamine precursors (levodopa and carbidopa), dopamine agonists (pramipexole, ropinirole, rotigotine and apomorphine), catechol-O-methyl transferase (COMT) inhibitors and monoamine oxidase B (MAO-B) inhibitors (selegiline, rasagiline and safinamid) [7]. Here, MAOB is linked to Parkinson disease.