Research sheds new light on Parkinson's disease treatment - - Drug Topics

ADVERTISEMENT

Research sheds new light on Parkinson's disease treatment


Drug Topics


Medical practitioners treating Parkinson's disease (PD) tend to focus on controlling patients' movement disorders. So said Monique Giroux, M.D., medical director of the National Parkinson Foundation Center of Excellence at the Cleveland Clinic Foundation. But for the patient, other disease-related symptoms are sometimes just as troubling as the motor disorders.

A number of major treatment centers are looking at PD patients more comprehensively. This has pharmaceutical implications, Giroux said. She spoke at a recent press conference in Washington, D.C., sponsored by the National Institute of Neurological Disorders & Stroke (NINDS). "These symptoms have started to receive a lot of attention only within the past half-decade or so," she said, "despite the fact that the hallucinations, dementia, and cognitive problems of PD increase the potential for placement into nursing homes, and the depression significantly worsens quality of life."

Over half of PD patients suffer depression, Giroux explained. And researchers think this is not just a reaction to the disease but rather a part of the biochemical abnormality, with a change in the neurotransmitters causing depression. Various antidepressant medications have proved helpful, Giroux said, including selective serotonin reuptake inhibitors (SSRIs) such as paroxetine and Zoloft (sertraline, Pfizer), as well as bupropion.

There's also much interest in and work on cognitive symptoms, due to their devastating impact on the quality of life. It appears that patients with dementia respond well to the acetylcholinesterase inhibitors, a class of drugs traditionally used with Alzheimer's patients. Some patients have improvement in cognitive measures, attention span, attention mechanisms, and sometimes even in their hallucinations, Giroux said. Ongoing studies are looking at various drugs for the visual hallucinations or psychoses result from dopaminergic agonist medicines. The two most commonly used dopamine agonists are ropinirole (Requip, GlaxoSmithKline) and pramipexole (Mirapex, Boehringer Ingelheim), Giroux said. She also noted that dystonia, a sustained involuntary muscle contraction that can be part of Parkinson's, can respond very well to Botox (botulinum toxin Type A, Allergan).

New methods are emerging for treating motor symptoms as well, said Giroux. Earlier guidelines suggest a dopamine agonist or levodopa for use as initial monotherapy for PD.

Levodopa is the gold standard in treating PD, extending the period that many patients can lead relatively normal lives. However, new strategies take into account that the first medicine used for patients in early Parkinson's could affect their symptoms later. "So there is a move toward a 'levodopa-sparing' strategy in support of alternative medicines such as the dopaminergic agonists. The two most commonly used medications in that category are ropinirole and pramipexole," said Giroux.

The levodopa-sparing strategy seems to be effective in delaying or reducing the motor complications and the on-and-off fluctuations in the duration of effectiveness of a drug, where the drug works one moment but wears off before the next dose is due. That creates a situation where practitioners can stratify patients, explained Giroux. This strategy seems to be best for younger patients who have greater risks of motor complications and dyskinesias but a lower risk of the medication-related side effects. They also have a longer time to live with Parkinson's.

On the other hand, she said, older patients don't have as many years to live with the disease and, as it happens, they tend to have fewer significant problems with the motor fluctuations and dyskinesias and greater risk for the side effects. So levodopa, which presents a slightly lower risk for these side effects, may be the better first choice for older patients, Giroux told the audience.

As research continues into other alternative medications, apomorphine (Apokyn, Mylan Bertek), an injectable dopaminergic agonist for advanced Parkinson's, can be used as a rescue therapy. As the patient's medication wears off and the next dose is not due for perhaps an hour or two, apomorphine can be used. While it has a very short duration of effectiveness, it is very fast-acting.

NINDS identifies Parkinson's as the second most common neurological disease in the United States, affecting half a million or more people. "After factoring in office visits, Social Security payments, nursing home expenditures, and lost income, the total cost to the nation is estimated to exceed $5.6 billion annually," Giroux noted.


Drug Topics Issue
Drug Topics is a monthly news magazine, guided by a board of pharmacy leaders, reporting on all phases of community, retail, and health-system issues and trends. We cover managed care and professional, national, and state activities as well as new therapies involving prescription and OTC drugs.
ARCHIVES | RSS | E-NEWS | DIGITAL EDITION

ADVERTISEMENT

ADVERTISEMENT

Survey
How would you rate your level of job satisfaction?
I love my job
I am reasonably satisfied
I am marginally satisfied
It's a job
I am very frustrated
I'm ready to change careers
View Results
I love my job
18%
I am reasonably satisfied
26%
I am marginally satisfied
12%
It's a job
13%
I am very frustrated
17%
I'm ready to change careers
14%
View Results

Modern Medicine logoDrug Topics archives are now available on ModernMedicine.com, a new online resource designed to meet the evolving needs of physicians.
Register now (it's free and quick) or Find out more.

Keep visiting Drug Topics for fresh content, news, opinions, editor's blogs and more.

ADVERTISEMENT

Source: Drug Topics,
Click here