How Does Parcopa Work?Dopamine deficiency (caused by a loss of dopamine-producing cells) in certain parts of the brain may be responsible for many of the symptoms of Parkinson's disease. Although it would make sense to give dopamine to help treat Parkinson's, this does not work, as dopamine cannot cross the blood-brain barrier to reach the brain. Levodopa is a precursor of dopamine, which means that the body can use levodopa to make dopamine. Unlike dopamine, levodopa crosses the blood-brain barrier.
Levodopa is almost always given in combination with carbidopa. Carbidopa delays the conversion of levodopa into dopamine until it reaches the brain, preventing or diminishing some of the side effects that often accompany levodopa therapy. Carbidopa also reduces the amount of levodopa needed for Parkinson's disease treatment.