COMT inhibitor

A COMT inhibitor is a drug that inhibits the action of catechol-O-methyl transferase. This enzyme is involved in degrading neurotransmitters. COMT inhibitors are used in the treatment of Parkinson's disease in combination with levodopa and a DOPA decarboxylase inhibitor because they inhibit levadopa degradation in the periphery, that is, outside the central nervous system (CNS).

Pharmaceutical examples include entacapone,tolcapone,opicapone and nitecapone. Tolcapone also acts inside the CNS.