Parkinson disease, the effect of levodopa, and the ELLDOPA trial

The introduction of effective doses of levodopa for the treatment of Parkinson disease (PD)(1,2) was a revolutionary step in overcoming symptoms of a progressive neurodegenerative disease. This took place a little more than 30 years ago, and still, today, levodopa remains the most effective drug for the reversal of symptoms of PD.(1,2) If there were no associated adverse effects with long-term use, treatment of PD would be a simple matter. But most of the physician's effort in providing optimum care of patients with PD is in trying to overcome all too common adverse effects of levodopa.