opicapone + levodopa + carbidopa

This drug is a **combination of opicapone, levodopa, and carbidopa**. Opicapone is a third-generation, peripherally-acting, long-acting, selective and reversible **catechol-O-methyltransferase (COMT) inhibitor**. Levodopa is a precursor of dopamine used as the primary symptomatic therapy in Parkinson's disease; it is converted to dopamine in the brain. Carbidopa is a **peripheral aromatic L-amino acid decarboxylase inhibitor** (dopa decarboxylase inhibitor), which prevents the peripheral conversion of levodopa to dopamine, thereby increasing its central availability. **Mechanism of action**: Opicapone inhibits peripheral COMT, increasing plasma half-life and bioavailability of levodopa by preventing its breakdown, which enhances and prolongs dopaminergic stimulation in the brain. Carbidopa reduces peripheral metabolism of levodopa by inhibiting dopa decarboxylase, further increasing its central availability and reducing peripheral side effects. The combination is used for the treatment of **Parkinson's disease and the management of "off" episodes (motor fluctuations) in patients using levodopa therapy**. The combination of all three agents allows for more stable and prolonged levodopa levels, reducing "off" time and improving motor symptoms in Parkinson's disease patients[1][2][3][6].