Gel Reduces Tremors in Parkinson’s Disease
Researchers study levodopa–carbidopa intestinal gel versus pill form (January 6)
An experimental treatment for Parkinson’s disease reduced by nearly 2 hours on average the period each day when medication failed to control patients’ slowness and shaking, according to results from a double-blind, phase III clinical trial published in Lancet Neurology.
The study compared a levodopa–carbidopa intestinal gel (AbbVie) with the same medication in pill form in patients with advanced disease.
Parkinson’s disease results from the loss of brain cells that make dopamine, which helps to control movement. As dopamine levels fall, patients experience tremors, muscle stiffness, and loss of balance. A commonly prescribed treatment, the levodopa–carbidopa combination, works as the body converts levodopa into dopamine and carbidopa escorts levodopa to the appropriate part of the brain. The problem is that patients face hours of uncontrolled slowness, freezing, and tremors each day — called “off-time” — as the treatment gets into place or wears off.
One reason for the break in treatment with levodopa–carbidopa is that the therapy comes in a pill, and the pill remains in the stomach for up to 6 hours before it is emptied into the small intestine. It is only there that levodopa encounters the proteins capable of transporting it into the bloodstream en route to the brain. Therefore, researchers envisioned a system that steadily delivers levodopa gel directly into the small intestine through a surgically placed tube and with the help of a pump worn on the belt.
Patients using the gel system saw an average reduction in daily off-time of 1.91 hours and an increase in “on-time” without troublesome dyskinesia of 1.86 hours compared with the pill form.