Treatment with dopaminergic agents, principally pergolide, and the development of dementia are risk factors for developing psychotic symptoms in patients with Parkinson’s disease, according to a report in the current issue of BMC Neurology.
“It is well known that treatment with dopamine agonists (drugs that work by directly activating dopamine agonist receptors) can cause psychotic episodes in Parkinson disease,” lead author Dr. Daniel Ecker, from the University of Ulm, Germany, told Reuters Health. Psychotic symptoms occur in less than 10 percent of untreated Parkinson’s disease patients, but in as many as 40 percent of those treated with dopaminergic medications.
“The novelty of this study is that we evaluated retrospectively the risk of different dopamine agonists to evoke this side effect,” Ecker added.
“The biggest finding was that pergolide treatment in our data set is one risk factor for psychotic symptoms and levodopa treatment was associated with the lowest risk to develop psychotic symptoms,” he noted.
The findings stem from a comparison of risk factors in 80 Parkinson’s disease patients with psychotic symptoms and 120 age-matched controls without such symptoms.
Dementia, number of other medications also being taken, and pergolide use, all positively correlated with psychotic episodes, the report indicates.
The risks of psychotic episodes with dopaminergic agents varied widely. As noted, levodopa had virtually no effect on the risk of such episodes, whereas pergolide use doubled the risk.
The results, the authors conclude, indicate that “Parkinson’s disease-associated psychosis correlates both with epidemiological factors and with the choice of different dopaminergic drugs. These factors might be included in differential therapeutic considerations to minimize the risk of psychosis.”
SOURCE: BMC Neurology, June 10, 2009.