Nov. 24, 2003 -- People with Parkinson's disease may become completely dependent upon a drug commonly used to help restore their muscle function and retain their independence.
A new report suggests the popular Parkinson's disease drug levodopa may be addictive, especially in people who use the drug and do not actually have Parkinson's disease.
Although more research is needed on the possible addictive properties of levodopa in people with Parkinson's, researchers say the findings may help explain why people with Parkinson's disease frequently crave their next dose of levodopa.
"Although the impatience, the emotional dependence, and the craving to receive the next dose of levodopa might resemble addiction, this behavior has been attributed to the urge to overcome the incapacitating motor dysfunction," write researcher Israel Steiner, MD, of Hadassah University Hospital in Jerusalem, Israel, and colleague.
Stopping Levodopa May Lead to Withdrawal
But in a report published in the Nov. 25 issue of the journal Neurology, researchers describe five people who displayed signs of addiction after being treated with levodopa for restless leg syndrome or an incorrect diagnosis of Parkinson's disease.
According to the report, the patients suffered from psychological and physiological symptoms of addiction and withdrawal from the levodopa when they were weaned off the drug.
For example, one woman with restless leg syndrome who took levodopa increased her dosage of the drug by seven times without consulting her doctor and suffered from agitation, palpitations, diarrhea, and sweating when doctors tried to replace levodopa with another drug.
Researchers say that because levodopa works on the same reward center of the brain that has been associated with the addictive properties of other drugs like cocaine, nicotine, and alcohol, it's plausible that addiction to levodopa may develop.
They say their observation of the potential addictive properties of levodopa should be examined in larger studies involving people with and without Parkinson's disease.