Used primarily in the treatment of Parkinson’s disease, it functions as a catechol-O-methyltransferase (COMT) inhibitor. By blocking this enzyme, it helps prolong the effect of levodopa, a medication that increases dopamine levels in the brain. This combination therapy is particularly beneficial for patients experiencing motor fluctuations, reducing "off" periods and improving overall symptom control. Its application is crucial in managing the progression of the disease and enhancing the quality of life for patients.