Friday, November 15, 2002
By Paula Moyer
For people with moderate to severe restless legs syndrome, help may be on the way in the form of medication delivered through a patch worn on the forearm, according to Dr. J. Carsten Moller.
Restless legs syndrome, which physicians often refer to as RLS, is a common condition marked by a discomfort in the legs and an irresistible urge to move them, with a worsening of symptoms at night. No medication has yet been approved in the United States to treat RLS; however, certain drugs that are used to treat Parkinson's disease seem to be effective.
In the current research, presented here at the at the Movement Disorders Society's Seventh International Congress of Parkinson's Disease and Movement Disorders, Moller and colleagues tested rotigotine, which belongs to a class of drugs known as dopamine agonists and is also being tested as a treatment for Parkinson's disease.
"The patch delivery method for this medication provides a continuous dose of medication and therefore seems to assure all-night relief of symptoms, without the need to get up at night and take more medication," Moller told Reuters Health. "It may also be more convenient for patients who would prefer not to swallow pills." He is a consultant in the neurology department at Phillips-University Marburg in Germany.
Rotigotine may have an advantage over other dopamine agonists, as well as levodopa--a mainstay of Parkinson's treatment that is often used to treat RLS. Levodopa has often been associated with augmentation, an annoying adverse effect characterized by an onset of symptoms earlier in the day and the involvement of other body parts, such as the arms. Dopamine agonists have occasionally been linked to augmentation as well, Moller said.
He and colleagues thought that the culprit triggering augmentation could be the immediate release of medication that occurs with oral formulations. Therefore, they sought to determine whether augmentation could be avoided if the medication was delivered through a patch on the skin. Rotigotine is easily absorbed through the skin, Moller said.
The investigators followed 63 patients assigned at random to one of four study groups. One group received an inactive placebo while the rest were given rotigotine in different doses: 1.125 milligrams (mg), 2.25 mg or 4.5 mg. The patients were followed for 7 days.
Moller found a "dose-dependent" response to rotigotine; in other words, the higher the dose, the greater the response. All three rotigotine groups had a greater response than placebo, with the greatest response seen in the 4.5-mg group. The investigators measured patients' response with a standard scale developed by the International Restless Legs Syndrome Study Group, an international group of RLS experts.
They saw no obvious differences among the groups regarding either local side effects on the skin where the patch was worn or system-wide side effects.
"These findings suggest that rotigotine is effective for treating moderate to advanced RLS," Moller said. However, he cautioned that the study did not involve a sufficient number of patients to draw definitive conclusions. Therefore, he and his colleagues are planning further studies with larger numbers of patients.
The investigation was sponsored by Schwarz Pharma, which manufactures
Copyright 2002 Reuters