Drug Reduces Early Parkinson's Symptoms
Side Effects of Experimental Drug Are Minimal
Dec. 16, 2002 -- An experimental drug may offer an improvement in symptoms for people with early-stage Parkinson's disease. In a newly published study, patients treated with the drug rasagiline had reduced symptoms with few of the side effects associated with currently available therapies.
Researchers say rasagiline was slightly less effective for controlling symptoms than either levodopa or dopamine agonists, the most widely used treatments for Parkinson's. But its better side effect profile may make it far more attractive to people with mild to moderate symptoms.
"This treatment is really intended for people who are not at the point where they need the big guns," lead researcher Andrew Siderowf, MD, tells WebMD. "The thing that separates it is its tolerability and ease of use."
Parkinson's disease is a progressive disorder of the central nervous system that affects 1-1.5 million Americans, including actor Michael J. Fox and boxer Muhammed Ali. It is caused by the death of nerve cells that normally produce dopamine, a brain messenger chemical involved in movement.
Developed in the 1960s, the drug levodopa effectively boosts dopamine levels. Dopamine-like drugs mimic the effects of dopamine but are also associated with side effects in many patients, including confusion, lightheadedness, sleepiness, hallucinations, and stomach problems.
Instead of creating more dopamine, rasagiline is believed to work by preventing the dopamine already present in the brain from being broken down. The new study, reported in the December issue of the Archives of Neurology, compared treatment with the experimental drug to treatment with placebo in 404 patients with early-stage Parkinson's.
Symptom relief was measured using a standardized scale assessing the ability to perform basic daily tasks and emotional well-being. At the end of the 24-week treatment period, patients taking rasagiline were found to have better control of physical symptoms and better emotional well-being than those taking placebo pills. Side effects were minimal for both groups.
Siderowf characterized the improvement in symptoms as "subtle but clinically relevant." Longer studies are under way, but manufacturer Teva Phamaceuticals, which funded the study, must win FDA approval before the drug can be prescribed in the United States.
While the experimental drug may offer more options for patients, a spokesperson for the Parkinson's Disease Foundation says it appears to be very similar to a drug already available for the treatment of early-stage disease, known as selegiline. Both drugs are similar in makeup and appear to have a good safety profile, but Parkinson's expert Cheryl Waters, MD, says selegiline has proven disappointing in delaying the progression of the disease. At least one preliminary report suggests that rasagiline may be more promising.
"This study did not address progression, but the hope is certainly that rasagiline will prove to delay the progression of Parkinson's," she tells WebMD.