Parkinson's patients stomach new drug better than conventional meds

Several studies conducted at Baylor College of Medicine in Houston show that a new kind of orally disintegrating tablet provides improved symptom relief for patients with Parkinson's disease. Results are reported in the current issue of the journal Therapy.

A new form of the medication selegiline, used for years to manage motor complications in Parkinson's patients, avoids first-pass metabolism and sidesteps compromises to its efficacy and tolerability. The drug is currently awaiting U.S. Food and Drug Administration approval for use as an adjunctive therapy to the drug levodopa in the management of the neurodegenerative disease.

"Although a variety of therapeutic options exist, there is a tremendous amount of unmet need in the treatment of Parkinson's disease," said co-author Dr. Joseph Jankovic, professor of neurology at BCM and director of the college's Parkinson's Disease Center and Movement Disorders Clinic.

Many patients with Parkinson's disease still experience several hours a day during which the effects of levodopa, the most frequently used drug in Parkinson's treatment, wear off to the extent that patients shake and cannot move. Besides the wearing-off effects, many patients experience jerky involuntary movements, called dyskinesias, at the peak effect of levodopa.

Because the orally disintegrating tablet dissolves within seconds, the drug can be delivered more effectively at a relatively low dose, reducing roughly two hours each day that a patient experiences debilitating symptoms, according to the studies' findings.

"The goal of treatment is to reduce the 'off' time and increase the 'on' time during which they are free from Parkinson's symptoms and dyskinesia," said Jankovic. "This unique formulation of selegiline delivers a more active drug without some of the troublesome side effects seen with standard selegiline. These study results offer hope to Parkinson's disease patients and the physicians who treat them."

Due to its fast-dissolving technology, the new form of selegiline bypasses the gut and first-pass hepatic metabolism and is primarily absorbed into the systemic circulation through the oral mucosa, the mucous membrane that covers all structures inside the mouth except the teeth.

Some Parkinson's patients also have difficulty swallowing, making this treatment a more convenient option than others. One of the studies reports that more than 90 percent of patients found the new selegiline easy to take, with 61 percent rating it extremely easy to take.

The Therapy article draws from results of three selegiline studies, whose patient populations totaled 517. BCM was one several international sites that participated. Dr. Anthony Clarke of the United Kingdom-based Amarin Neuroscience was a co-author of the paper.