Dopamine agonists and ischemic complications in Parkinson's disease: a nested case-control study

Background It has been suggested that ergoline dopamine agonists can cause ischemic complications. The effect of dopamine agonists in general on the prevalence of ischemic events in patients with Parkinson's disease (PD) has not been studied. Objective Our aim was to investigate the association between the use of dopamine agonists and hospitalization due to ischemic events in patients with PD. Methods We performed a nested case-control study using the PHARMO Institute for Drug Outcome Research database. All patients issued at least one prescription for levodopa after the age of 55 years between 1994 and 2006 were initially identified. Cases were patients who were hospitalized for the first time after November 1997 for an ischemic event and were matched to as many as four controls. Exposure to dopamine agonists during the year preceding the index date was identified. Results The study population consisted of 542 cases and 2,155 controls. The mean effect of dopamine agonist use 1 year prior to the index date on ischemic events requiring hospitalization is shown with 95% probability in the 0.95-1.49 range. Stratified results according to the type of dopamine agonist showed no risk differences between ergoline and nonergoline agonists. Conclusions This study does not support an association between dopamine agonist use and an increased risk of ischemic events requiring hospitalization.