The Sound of Evolution
Tolcapone
Mechanism of action:
Tolcapone is a catechol-O-methyltransferase inhibitor and is commonly used as an adjunct to levodopa. Peripheral catechol-O-methyltransferase breaks down levodopa and reduces the proportion that can enter the central nervous system, whereas tolcapone inhibits peripheral catechol-O-methyltransferase activity and helps more levodopa enter the central nervous system for conversion into dopamine. In addition, tolcapone also inhibits catechol-O-methyltransferase within the central nervous system, prolonging dopamine activity in the synaptic cleft and improving the stability and availability of central dopaminergic signaling.
Reference(s):
1. Guay DR et al. (1999). Tolcapone, a selective catechol-O-methyltransferase inhibitor for treatment of Parkinson's disease. Pharmacotherapy.
2. Keating GM et al. (2005). Tolcapone: a review of its use in the management of Parkinson's disease. CNS Drugs.
3. Truong DD et al. (2009). Tolcapone: review of its pharmacology and use as adjunctive therapy in patients with Parkinson's disease. Clin Interv Aging.