Opicapone is primarily used as an adjunct therapy in the treatment of Parkinson's disease. It is specifically prescribed to enhance the effectiveness of levodopa, a standard medication for managing Parkinson's symptoms. By inhibiting the enzyme catechol-O-methyltransferase (COMT), opicapone helps to prolong the duration of levodopa's action in the brain. This results in more stable and consistent control of motor symptoms, such as tremors, stiffness, and bradykinesia, reducing the frequency of "off" periods when symptoms worsen. It is typically taken once daily, offering convenience and improved adherence for patients. Opicapone is particularly beneficial for individuals experiencing motor fluctuations despite optimized levodopa therapy.