FDA has approved carbidopa-levodopa (Duopa, AbbVie) enteral suspension for the treatment of patients with advanced Parkinson’s disease.
Parkinson’s disease is a chronic, progressive, neurodegenerative condition characterized by tremor, muscle rigidity, slowness of movement and postural instability. Parkinson’s disease results from the degeneration of dopaminergic neurons in the brain however, the cause of this degeneration remains unknown. In the United States, it is estimated that 1 million people suffer from Parkinson’s disease occurring most commonly in the elderly population, with a mean age of onset of 65 years.
As Parkinson’s disease progresses, patients start to develop motor fluctuations which oscillate between “off” times, a state of poor mobility, and “on” times, or periods when the medication is working and symptoms are controlled. The goal of treatment is to reduce “off” time as much as possible.
Duopa is a combination of levodopa, which is converted to dopamine once it crosses the blood brain barrier, and carbidopa, which inhibits the peripheral breakdown of levodopa to increase availability to the brain. It is an enteral suspension that is administered using a small, portable infusion pump that delivers the drugs directly into the small intestine for 16 continuous hours. Long-term administration requires placement of PEG-J (percutaneous endoscopic gastrotomy procedure with jejunal extension) tube for intestinal infusion.
In Parkinson’s disease, the spontaneous emptying of the stomach becomes delayed and unpredictable which can affect the timing of when orally administered drugs leave the stomach and are absorbed in the small intestine, therefore delaying time of onset. The intestinal infusion allows the bypass of the stomach to eliminate this problem.
Duopa is approved for the treatment of motor fluctuations in patients with advanced Parkinson’s disease. FDA approved Duopa as an orphan drug, which designates a product that is intended for the treatment of a rare disease or condition. Approval is based on a clinical trial that compared the safety and efficacy or Duopa to oral, immediate-release carbidopa-levodopa tablets in advanced Parkinson’s disease patients. In the study, Duopa significantly reduced daily mean “off” time and improved mean “on” time when compared to carbidopa-levodopa IR tablets. Some of the most common adverse events associated with Duopa were complication of device insertion, nausea, constipation, incision site redness, dyskinesia, and depression.
Erin Bastick is a PharmD Candidate 2016, Ohio Northern University, Ada, Ohio, and an inpatient intern at University Hospitals, Cleveland.