Levodopa in the treatment to impulse control disorder in patients with Parkinson’s disease

This study investigated whether abnormal behavior in patients with Parkinson’s disease (PD) and impulse control disorder (ICD) was affected by a change in drug treatment. Researchers suggested that switching from dopamine agonists to levodopa/carbidopa improved ICD outcomes and daily activities.

ICD is present in roughly 15% of patients with Parkinson’s disease being treated with dopamine agonists. ICD is a failure to resist an urge or an impulse. Treating ICD is often challenging as it increases the stress in the patient, his family or caregivers.

Prior studies showed that reducing the dopamine agonist doses or switching the treatment to levodopa is associated with a decrease in ICD symptoms. However, behavioral interventions are sometimes needed for some patients. It is important to research if switching to slow-release levodopa/carbidopa can help with ICD in patients with PD.

This study included 50 patients with PD treated with dopamine agonists who developed ICD and switched their medication to levodopa. These patients were compared to 2 other groups of patients (group A and B). Group A consisted of 60 patients with PD treated with dopamine agonists and with no signs of ICD. Group B had 40 patients with Parkinson’s disease who did not receive any treatment. ICD levels were assessed before and 12 weeks after treatment initiation.

At the beginning of the study, patients with ICD showed increased levels of mental symptoms such as anxiety, anger, and obsessive-compulsive behavior when compared to groups A and B. At 12 weeks after switching treatment, ICD significantly improved in these patients.

5.3% of the ICD group experienced dopamine agonist withdrawal syndrome (physical and mental symptoms that result from when you stop taking a drug). Another 5.3% of patients in the ICD group experienced a worsening of PD. All these patients dropped out of the study due to these side effects.

This study determined that switching from dopamine agonists to levodopa improves ICD in patients with Parkinson’s disease.

This study included a very small number of patients and had a rather short follow up period. Larger and longer studies are needed to evaluate the long-term effects of switching PD medications on behavioral and PD symptoms.