Parkinson's drug effective in treating restless leg syndrome
ST. PAUL, Minn. – Pergolide, a drug commonly used to treat Parkinson's disease symptoms, has recently been shown to be effective in treating restless legs syndrome. Researchers from seven countries collaborated on the study, published in the April 27 issue of Neurology, the scientific journal of the American Academy of Neurology.
Restless legs syndrome (RLS), characterized by sensory and motor abnormalities of the limbs associated with an urge to move, affects five to 10 percent of the population. RLS can lead to severe sleep disruption and daytime fatigue, compromising one's ability to function normally. People with RLS may be compelled to get out of bed several times during the night to walk or otherwise move their legs to relieve pain or discomfort. Though RLS was initially described in 1945, most affected individuals remain undiagnosed and untreated.
"Previous studies have indicated the efficacy of pergolide in treating RLS," notes study author Claudia Trenkwalder, MD, Department of Clinical Neurophysiology at Georg August University, Goettingen, Germany. "However, they generally included small numbers of patients orwshort durations of treatment, limiting conclusions regarding the clinical use of pergolide therapy." Trenkwalder and other researchers collaborated on this prospective, placebo-controlled longitudinal study designed to determine the efficacy as well as the long-term effects of pergolide in treating RLS.
One hundred RLS patients ages 18 to 75 were enrolled in the study through 17 medical centers in seven countries (Australia, Belgium, Finland, Germany, Italy, Netherlands, Spain). This prospective study, conducted from September 1998 through July 2000, consisted of two phases: a double-blind, parallel, randomized six-week comparison of pergolide versus placebo; and a long-term extension in which responders to either pergolide or placebo in phase one continued to receive blinded medication, and non-responders received open-label pergolide for up to 12 months of total study treatment. Prior to treatment, domperidone (an anti-nausea medication) was administered to all patients for 10 to 14 days. This measure was considered necessary to maintain investigator blinding as pergolide is known to cause nausea.
Primary efficacy measures were sleep efficiency and periodic limb movements during sleep (PLMS). Severity of RLS was assessed by the validated International RLS Scale.
In phase one, pergolide reduced PLMS arousal index versus placebo and improved RLS severity scores, though it did not improve sleep efficiency. Patients also reported improved quality of sleep. After 12 months (phase two), double-blinded pergolide patients maintained improvements, and placebo patients switched to open-label pergolide exhibited marked improvements in PLMS arousal index. Nausea and headache were experienced more frequently with pergolide than with placebo treatment.
"Our study demonstrates that pergolide substantially improves PLMS measures and subjective sleep disturbance associated with RLS," concludes Trenkwalder. "We are also satisfied by how well-tolerated the low-dose pergolide treatment was, and that its efficacy was maintained over the long term."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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