The combination of levodopa and carbidopa is used to treat the symptoms of Parkinson's disease and Parkinson's-like symptoms that may develop after encephalitis (swelling of the brain) or injury to the nervous system caused by carbon monoxide poisoning or manganese poisoning. Parkinson's symptoms, including tremors (shaking), stiffness, and slowness of movement, are caused by a lack of dopamine, a natural substance usually found in the brain. Entacapone is an inhibitor of catechol-O-methyltransferase (COMT). It is used in combination with levodopa and carbidopa (Sinemet) to treat the end-of-dose 'wearing-off' symptoms of Parkinson's disease. Entacapone helps the levodopa and carbidopa work better by allowing more of it to reach the brain, where it has its effects.
For more information on Stalevo (Carbidopa/Levodopa/Entacapone), click here