Duopa was approved in 2015 by the U.S. Food and Drug Administration (FDA) for Parkinson's motor symptoms (tremor, slowness, stiffness). A gel of levodopa and carbidopa, it is infused through a surgically implanted tube into the small intestine, where levodopa is absorbed. (Levodopa is converted in the brain to dopamine, the chemical that goes missing in Parkinson's; carbidopa helps levodopa get into the brain and decreases side effects.)
A portable pump, which can be worn during regular daily activities, infuses Duopa for 16 hours each day. Duopa is most often used in people who experience significant "off" time (when medication is not working optimally and symptoms return) and/or dyskinesia (involuntary, uncontrolled movement).
Duopa bypasses the stomach which, in Parkinson's, can empty slowly and irregularly. This can lead to poor absorption and unpredictable relief with drugs taken by mouth. The continuous infusion aims to keep a steady and consistent level of levodopa in the blood (and therefore in the brain) to lessen "off" time and dyskinesia.
For people who experience significant "off" time and dyskinesia and who do not want to or cannot undergo deep brain stimulation because of cognitive problems or other conditions, Duopa may be an alternative.
Cons and Complications
Potential side effects related to levodopa include nausea, low blood pressure (which can lead to dizziness and lightheadedness) and hallucinations.
The surgically implanted tube brings additional risks, including infection, bleeding, and tube clogging or dislodging. Family members or care partners also may have to help keep the tube clean and administer the medication.