L-dopa, also called levodopa, is a form of the amino acid dopa. Amino acids are organic acids that make up all the proteins and other compounds in living things. Doctors use L-dopa as a drug to relieve the symptoms of Parkinson disease, a disorder of the brain that causes trembling hands, rigid muscles, slow movement, and problems with balance.
The cause of Parkinson disease is unknown. Symptoms of the disease are associated with the destruction of nerve cells in a certain region of the brain. The loss of these cells results in a loss of dopamine, a chemical that the nerve cells use to communicate with the rest of the brain. Treatment with the drug L-dopa replaces the missing dopamine and so can relieve the symptoms, though it cannot cure the disease. However, long-term use of L-dopa can lead to side effects, such as nausea, abnormal movements, abrupt changes in muscle control, sleeplessness, vivid nightmares, hallucinations, and confusion.
Doctors first used L-dopa to treat Parkinson disease in the 1960’s. They usually add a drug called carbidopa, which delays the conversion of L-dopa into dopamine. Carbidopa helps to reduce the side effects of L-dopa and reduces the amount of L-dopa needed.
See also Parkinson disease .
