(RxWiki News) Earlier this year, a French man claimed that the drugs he was taking for Parkinson's disease made him addicted to gambling. Adding support to these claims, a new study shows that Parkinson's drugs can lead to impulse control problems.
Researchers from the Mayo Clinic have found that dopamine agonists - a class of drugs used to treat Parkinson's disease - can cause patients to develop impulse control disorders. Throughout the two-year period of the study, more than 20 percent of patients taking drugs such as pramipexole (Mirapex) and ropinirole (Requip) developed an impulse control disorder.
dailyRx Insight: Parkinson's patients taking dopamine agonists should be aware of personality control issues
The Mayo Clinic researchers - led by Anhar Hassan, M.B., B.Ch. - also found that the risk of developing an impulse control disorder increased as the dose of the drug increased. One in four patients who were taking medium doses developed an impulse control disorder, while one in three patients taking the highest doses developed an impulse control disorder.
According to Dr. Hassan, lowering doses or stopping the medication altogether can fix the problem within a few days to a month.
Impulse control disorders include pathological gambling, hypersexuality, binge eating, spending, and excessive computer use.
The National Institutes of Health estimate that half a million people in the United States suffer from Parkinson's disease, and other estimates state that figure may be much higher. Parkinson's disease is a neurodegenerative disorder that results from the death of neurons in a part of the brain called the substantia nigra, the cells that make the neurotransmitter dopamine. The primary symptoms are a resting tremor (disappears when a patient goes to make a movement), rigidity (stiffness of muscles), bradykinesia (slowness of movment, often seen as a shuffling walk), and unstable posture which leads to frequent falls. As the disease progresses, patients often experience dementia, with changes in mood, cognition, behavior, and thoughts. Depression and anxiety are also common, and psychosis has been seen in late PD. Diagnosis is made from symptoms and neurological exams, but there is no lab test that will clearly identify the disease. If symptoms improve when patients are given drugs to treat Parkinson's disease, the diagnosis is usually confirmed. There is no cure, only treatment of symptom. The primary medications used are levodopa (Sinemet, Atamet), dopamine stimulators (Mirapex, Requip, Parlodel) and MAO-B inhibitors (Eldepryl, Deprenyl, Azilect). Intractable Parkinson's has been treated with a surgical technique called deep brain stimulation.
The Mayo Clinic study appears online in the February 2011 issue of Parkinsonism and Related Disorders.