Rationale for dopamine agonist use as monotherapy in Parkinson's disease

Dopamine agonists are increasingly being used in the initial treatment of patients with de-novo Parkinson's disease because they provide symptom relief and a low risk of the dyskinesia frequently associated with levodopa. Evidence is also mounting in preclinical models that dopamine agonists protect dopaminergic neurons from the toxic effects of oxidative stress and the by-products of dopamine and L-dopa metabolism. Ergot derivatives, such as pergolide, induce minor side-effects and provide significant and sustained improvements in motor function in patients with early Parkinson's disease. Dopamine agonists also appear to reduce the loss of functional dopamine transporters when used early in the disease course, and these factors combine to build a case for the use of dopamine agonists in early-stage Parkinson's disease.