NCIt definition : A nitrocatechol compound with anti-parkinsonian property. Entacapone is a selective
and reversible inhibitor of catechol-O-methyltransferase (COMT), which catalyzes the
transfer of the methyl group of S-adenosyl-L-methionine to the phenolic group of substrates
that contain a catechol structure including dihydroxyphenylalanine (DOPA), catecholamines
(dopamine, norepinephrine, and epinephrine) and their hydroxylated metabolites. When
administered in conjunction with dopaminergic agents such as L-DOPA, entacapone prevents
the metabolism and inactivation of adjunct drugs, thereby increasing the bioavailability
of these compounds by facilitating their passage across the blood-brain barrier.;