Dopamine agonists in Parkinson's disease.
Levodopa (LD), the immediate precursor of dopamine, is the most effective agent in the treatment of Parkinson's disease (PD). While quite successful in treating the primary motor deficits of PD, most patients eventually develop LD-related motor fluctuation, dyskinesias and other adverse effects associated with chronic LD therapy. There is also concern that LD is neurotoxic, although this has not been demonstrated in any in vivo studies. Dopamine agonists (DAs) have been shown to be about as effective as LD in symptomatic treatment of mild-to-moderate PD. In addition, there is a lower tendency to develop motor fluctuations and dyskinesias with DA treatment than after initiation of therapy with LD. Furthermore, there is preclinical and clinical data to suggest a slowing of neurodegeneration with DAs. The adverse effects of DAs are similar to those experienced with LD, except that the ergot agents are associated with a small risk of tissue fibrosis not noted with the non-ergot DAs.
Tintner
Ron
R
Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, 6550 Fannin, #1801, Houston, Texas 77030, USA. rtintner@bcm.tmc.edu
Jankovic
Joseph
J
D002986:Clinical Trials as Topic; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004333:Drug Administration Routes; D004334:Drug Administration Schedule; D006801:Humans; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D010300:Parkinson Disease / Q000188:drug therapy*
D018491:Dopamine Agonists; D018696:Neuroprotective Agents