Side effects of prolonged therapy with levodopa in Parkinson's disease

We selected among 258 patients with the diagnosis of Parkinson's disease and parkinsonism, those patients with Parkinson's disease treated with levodopa and an inhibitor of the peripheral decarboxylase and who were being followed in our center. A total of 106 patients were evaluated in a transversal study of 6 months duration. We analyzed the age at presentation, the severity of disease by the Hoehn and Yahr's scale, the average time of evolution, other treatment besides levodopa and the secondary effects. We detected side effects in 41 patients. The most frequent one was fluctuations and they appeared more often in patients whose disease had begun before age 60, had begun with stiffness and/or bradykinesia, in patients with a more advanced clinical course and with longer evolution and therefore with longer treatment. We found a higher number of secondary effects in those patients who had also been treated with bromocriptine and/or amantadine. After analyzing the relations among the different variables, we found as we expected, a significant relation between the length of evolution and the clinical severity at the moment; nevertheless there was not a significant relation between these variables and the patient's age at the time the disease began and the form of presentation.