COMMON BRAND NAME(S): Tasmar
GENERIC NAME(S): TOLCAPONE
Description: Tolcapone is a reversible peripheral catechol-O-methyltransferase (COMT) inhibitor used as an additional drug to levodopa/dopa-decarboxylase inhibitor therapy for the symptomatic treatment of Parkinsonian syndromes or for those experiencing ‘end-of-dose’ deterioration.
Absorption: Rapidly absorbed from the GI tract. Peak plasma concentration: within 2 hr. Absolute bioavailability: 65%. Food delays and decreases the absorption.
Distribution: Protein-binding: >99% (mainly albumin). Not widely distributed into body tissues.
Metabolism: Extensively metabolised, mainly by conjugation to inactive glucuronide, some by catechol-O-methyltransferase and cytochrome P450 isoenzymes CYP3A4 and CYP2A6.
Excretion: Excreted via urine (60%) and faeces. Elimination half-life: 2-3 hr.