More Evidence that Dopamine Agonists Are Not Neuroprotective for Parkinson Disease

Whether dopamine agonists could be neuroprotective or disease-modifying for Parkinson disease (PD) is controversial. Cell culture and animal studies suggested that this class of medications might reduce dopaminergic cell loss, possibly via a mitochondria-mediated antiapoptotic mechanism. Researchers have now tested this neuroprotection hypothesis, examining the clinical and neuroimaging effects of early versus delayed pramipexole. They recruited PD patients within about 2 years after diagnosis at one of 98 centers. Randomized patients received double-blind placebo (274 patients) or pramipexole (1.5 mg per day; 261 patients). The primary outcome variable was the change from baseline in the total Unified Parkinson's Disease Rating Scale (UPDR…