Traditionally, Parkinson disease patients receiving medication have been given levodopa for treatment. In recent years a newer class of drug called dopamine agonists has been used to disable muscle control problems often associated with the disease.

Rebecca Stowe, University of Birmingham, reports in a study, that appears in the latest issue of The Cochrane Library (published by an international organization that evaluates medical research), reports that patients taking dopamine agonists were more than twice as likely to quit treatment. She suggest that the reason is because the severe side effects from dopamine agonists diminish a patient’s quality of life and outweighs the benefit of muscle control.

In Stowe’s study she and colleagues reviewed 29 studies that included 5,247 patients who were in the early stages of Parkinson’s disease and did not show significant signs of muscle and movement problems. There appeared to be no significant difference in the death rate between dopamine agonists and those who did not take drugs.

According to researchers it remains unclear the balance of risks and benefits of dopamine agonists. Currently the researchers are tracking another issue that was raised during their preliminary research–the link of dopamine agonists and impulsive behaviors like gambling and hypersexuality.