Key takeaways
Entacapone (Comtan) and Sinemet (carbidopa/levodopa) are both used to treat Parkinson's disease (PD), but they work differently. Entacapone is a COMT inhibitor that helps levodopa last longer in your body by blocking a protein that breaks it down. You must take it with each dose of carbidopa/levodopa for it to work. Sinemet, on the other hand, is a combination of carbidopa and levodopa. Levodopa turns into dopamine in your brain to relieve PD symptoms, while carbidopa prevents levodopa from breaking down before it reaches your brain. Sinemet is a first-choice option for PD and comes in various forms, including immediate-release and extended-release tablets. Entacapone and Sinemet are both available in both brand-name and generic forms. Both medications can cause side effects like involuntary movements and nausea, but Entacapone can also cause diarrhea and stomach pain. Both medications can make you very sleepy and may cause dark-colored urine, but Sinemet may also cause dark-colored sweat or saliva.
