Medications such as Levodopa, designed to alleviate PD symptoms and improve quality of life, and others like the type-B monoamine oxidase (MAO-B) inhibitor, catechol-O-methyltransferase (COMT) inhibitor, and dopamine agonists have been developed and prescribed to address the drawbacks of Levodopa [117]. Here, COMT is linked to Parkinson disease.