FDA OKs Drug for Parkinson's Dementia

Drug, Called Exelon, Is Already in Use for Alzheimer's Dementia

Medically Reviewed by Louise Chang, MD on June 28, 2006

June 28, 2006 -- The FDA approved today the drug Exelon to treat mild to moderate dementia associated with Parkinson's disease.

Parkinson's disease is a chronic, progressive neurological disease. It results from the gradual destruction of nerve cells in the part of the brain that controls body movements. Symptoms include shaking (tremor), weakness, and muscle stiffness.

Exelon isn't a new drug. The FDA had previously approved it to treat mild to moderate Alzheimer's dementia, the most common type of dementia in older adults.

Parkinson's disease becomes more common with advanced age; so does dementia. But those conditions aren't part of the normal aging process.

The FDA estimates that less than 1% of people over age 65 are affected by Parkinson's dementia (0.2% to 0.5%). Parkinson's dementia symptoms include problems with memory, attention, planning, impulse control, and reasoning (executive function).

FDA's Comments

Steven Galson, MD, MPH, director of the FDA's Center for Drug Evaluation and Research, commented on Exelon's new approval in an FDA news release.

"It's been recognized for almost a decade that the dementia of patients with Parkinson's disease differs from the dementia of patients with Alzheimer's, but until now, there has been no treatment that has been shown to be effective specifically for the dementia associated with Parkinson's disease," Galson states. "Today's approval of Exelon helps to fill this medical need."

However, Exelon isn't a cure for dementia. The drug is designed to slow the progression of dementia, not to reverse dementia.

Drug's Trial

The FDA approved Exelon as a Parkinson's dementia treatment based on the results of a clinical study.

The study included 541 patients who showed symptoms of mild to moderate dementia at least two years after being diagnosed with Parkinson's disease. The patients were randomly assigned to take either Exelon or a placebo (sham treatment) for six months. They didn't know whether they were taking Exelon or the placebo.

At the end of the six-month trial, the condition of the Exelon-treated patients, as shown on a scale that measures mental processes, was significantly better than the condition of the patients on placebo, according to the FDA.

Drug's Side Effects

Exelon has been associated with "significant gastrointestinal adverse reactions," states the FDA.

In clinical trials, 47% of the patients treated with Exelon developed nausea, and 26% of women and 18% of men on high doses of Exelon experienced significant weight loss.

Other common adverse events reported by patients on Exelon include vomiting, appetite loss, indigestion, and strength loss. In some patients with Parkinson's disease, Exelon treatment was associated with a worsening of tremor, according to the FDA.

Exelon is made by Novartis Pharmaceutical Corp. Novartis is a WebMD sponsor.

Show Sources

SOURCES: News release, FDA. WebMD Medical Reference: "Understanding Parkinson's Disease - the Basics." National Institutes of Mental Health: "Teenage Brain: A Work in Progress."

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