Taking oral medications can present challenges for Parkinson’s disease patients. The “duopa pump,” FDA-approved in 2015 for advanced Parkinson’s disease, offers the alternative of bypassing the stomach and providing a steady drug infusion over 16 hours. The pump supplies carbidopa/levodopa combination therapy – a powerful tool in managing Parkinson’s disease symptoms since the mid-1970s. By targeting the premature loss of dopamine-producing neurons in the brain that causes major motor symptoms (stiffness, tremor, and slowness), the therapy has greatly improved quality of life and life expectancy for many patients.
Pumps are gaining popularity despite the tradeoff of a bulky unit and mechanical failure risks, according to neurologist Thomas Davis, M.D., of Vanderbilt University Medical Center. “It’s not for every patient, but for those who have side effects or where the lapse between oral doses produces anxiety or a dive in their functionality, it can mean a huge quality of life improvement,” Davis said.
“For those who have side effects or where the lapse between oral doses produces anxiety or a dive in their functionality, [pumps] can mean a huge quality of life improvement.”
Oral vs. Pump Delivery
For some patients, swallowing pills carries risks of choking or aspiration. Nausea and constipation are common side effects. For many, the biggest problem with pills is the inconsistency of the support they provide. “It’s bad enough to be tied to your clock to take pills every two hours, but patients can also face big fluctuations in how they feel, depending on where they are in that two-hour cycle,” said Steven Afrow, M.S.N., nurse practitioner in the Division of Movement Disorders at Vanderbilt.
Davis adds, “Their inclination may be to overdose on the pills to avoid that happening. That can mean side effects from nausea and dyskinesia all the way to hallucinations or dangerous compulsive behaviors.”
Duopa offers an enteral drug suspension delivered through a stoma and absorbed through the small intestines to mitigate these risks. The pump also enables precise titration at the patient’s individual “sweet spot.” “I can’t tell my patients to cut their pills up and take 173 mgs every two hours, but I can set their machine for the equivalent to that dosage,” Afrow said.
A Multidisciplinary Effort
Today, pump users constitute less than five percent of Vanderbilt’s Parkinson’s patients, Afrow said, but this is about double the number two years ago and appeal is growing. “I’ve seen people take great turns in their lives’ direction by switching to the pump.”
As a Parkinson’s Center for Excellence, Davis, Afrow and their colleagues in movement disorders, surgery and interventional radiology must all work together to provide this option. Said Davis, “It takes all these resources to be able to offer the pump. Because we are a large institution, we can do this, but for smaller centers or private practices, it is generally just not possible.”
Some pump users drive as long as six hours for monthly visits. “The Parkinson’s community is very active and much of the increase in pump use is due to word-of-mouth referrals. For some patients, it provides a physical and psychological ‘new lease on life,’” Davis said.
“I’ve seen people take great turns in their lives’ direction by switching to the pump.”
Discerning Good Candidates
For all the pump’s benefits, Afrow says they take a measured approach to offering the option. “If oral meds are working, we stop there. If not, we are still careful to recommend pumps only to patients who have the mental and physical capacity to manage both the stoma and the pump, with its attendant tubing, or have a caregiver who can. I have to build a relationship first to answer these questions,” he said.
Davis typically offers the duopa pump to the same patients who are candidates for deep brain stimulation. “The decision really hinges on what is optimal for that individual: invasive surgery with its small stroke risk, or the ongoing use of the pump,” he said.