Key takeaways
Entacapone (Comtan) and ropinirole (Requip) are both used to treat Parkinson's disease (PD), but they work differently and have different uses. Entacapone is a COMT inhibitor that helps carbidopa/levodopa work better by blocking a protein that breaks down levodopa before it reaches the brain. You need to take it with each dose of carbidopa/levodopa. Ropinirole, on the other hand, is a dopamine agonist that mimics dopamine in the brain and can be used alone. It also treats restless legs syndrome (RLS). Entacapone is taken multiple times a day with carbidopa/levodopa, while ropinirole can be taken three times a day or once daily if using the extended-release form. Both medications can cause sleepiness and dizziness, but ropinirole can also cause compulsive behaviors and hallucinations. Entacapone is available in both brand-name and generic forms, while ropinirole is only available as a generic.
