Five years' treatment of Parkinson's disease with levodopa. Therapeutic results and survival of 100 patients.

One hundred patients with Parkinson's disease, who started taking levodopa before the end of 1968, have been assessed after 5 years. Forty-seven patients are still being followed on levodopa, and half of them are at least 25% better than at their pretreatment evaluation. However, the average functional rating is returning toward baseline from its remarkable improvement at 1/2 to 2 years. Abnormal involuntary movements, rapid oscillations in motor performance, postural instability, and dementia have become the major adverse effects. Thirty-two of the 100 patients have died. Life-table analysis shows an excess mortality of 1.9 compared with the U.S. population, a figure that is lower than the 2.9 reported before levodopa's use. Despite its inability to cure Parkinson's disease, levodopa provides symptomatic relief for a prolonged time and it remains the single most effective medication for the illness.