Key takeaways
Tolcapone (Tasmar) and carbidopa/levodopa (Duopa) are both used to treat Parkinson's disease (PD), but they work in different ways and have different uses. Tolcapone is a catechol-O-methyltransferase (COMT) inhibitor that is used as an add-on treatment to carbidopa/levodopa when symptoms are not well controlled. On the other hand, Duopa is a combination of carbidopa and levodopa, which replaces dopamine in the brain and is used for movement problems related to advanced PD. Duopa is delivered through a PEG-J tube with an infusion pump, while tolcapone is taken orally. Tolcapone can cause serious liver damage and requires regular liver monitoring, whereas Duopa can cause stomach problems due to the tube placement. Both medications can cause sleepiness and changes in behavior. Tolcapone is available as a lower-cost generic, while carbidopa/levodopa is only available as a branded medication.
