Epilepsy Drug May Treat Parkinson's
The epilepsy drug zonisamide may help curb the tremors and other movement problems of Parkinson's, a Japanese study shows.
Jan. 4, 2007 -- The epilepsy drug
zonisamide may help curb the tremors and other movement problems of
Parkinson's, a Japanese study shows.
Zonisamide is sold in the U.S. generically and under the brand name
disease, the brain cells that make dopamine, a chemical that helps
control the body's movements, gradually falter and die. Symptoms include
tremor, movement problems, and unsteady balance.
The disease usually starts between the ages of 50 and 65. There is no cure,
but medications can help manage Parkinson's symptoms.
The new study on zonisamide for Parkinson's comes from researcher Miho
Murata, MD, PhD, of Japan's National Center of Neurology and Psychiatry, and
colleagues. It appears in the Jan. 2 issue of Neurology.
Murata's team studied 279 Japanese Parkinson's patients then taking levodopa
and other Parkinson's drugs.
The patients had shown "insufficient response" to those drugs, the
They note that the patients had been taking levodopa doses lower than those
typically used in the U.S., but said they probably weren't undertreated.
The researchers randomly assigned patients to take either zonisamide in one
of three doses (25, 50, or 100 milligrams) or a placebo every day for 12
All the patients were required to keep taking their levodopa and were
allowed to continue any other Parkinson's drugs they were using before the
The researchers tracked changes in the patients' movement problems during
the 12-week study.
Patients taking the zonisamide showed more improvement in their Parkinson's
movement symptoms than those on the placebo.
Those benefits included a drop in Parkinson's-related tremors and
However, zonisamide didn't cure Parkinson's or completely relieve movement
Zonisamide trumped the placebo regardless of dosage.
The percentage of patients with at least a 30% drop in Parkinson's movement
- Placebo: 22%
- 25 mg/day zonisamide: 35%
- 50 mg/day zonisamide: 39%
- 100 mg/day zonisamide: 32%
Patients taking 50 or 100 mg/day of zonisamide had the least amount of daily
"off time" -- time when their medication had worn off.
Zonisamide was "safe, effective, and well tolerated," the
The drug's side effects -- which included sleepiness, apathy, weight
loss, and constipation -- were more
common with the 100 mg daily dose.
The researchers aren't recommending zonisamide for Parkinson's disease yet.
They say longer, more diverse studies are needed.
It's not clear how zonisamide eased Parkinson's symptoms. Murata's team says
the drug may boost dopamine production, but they didn't test that theory.
The study was funded by Dainippon Sumitomo Pharma, which developed
zonisamide. Zonegran is now licensed exclusively by the drug company Eisai.