Key takeaways
Tolcapone (Tasmar) and carbidopa (Lodosyn) both help to manage symptoms like shakiness and slowed movement in people living with Parkinson's disease (PD). But they are in different medication classes and have some important differences. Tolcapone is a catechol-O-methyltransferase (COMT) inhibitor, while carbidopa is a decarboxylase inhibitor. Tolcapone is used as an add-on treatment with carbidopa/levodopa when symptoms aren't well-controlled, whereas carbidopa is taken with levodopa to help more of it reach the brain. Tolcapone is taken three times a day, while carbidopa's dosing depends on your carbidopa/levodopa dose and can be taken up to four times a day. Tolcapone can cause serious liver damage and requires regular liver monitoring, while carbidopa can cause changes in behavior and thoughts, including hallucinations and impulsive behavior. Both medications can cause sleepiness. Both medications are avaiblle as a generic.
