Mortality associated with early and late levodopa therapy initiation in Parkinson's disease

Abstract

We evaluated the possible influence of early levodopa treatment on the mortality of Parkinson's disease (PD). One hundred forty-five consecutive parkinsonian patients initiated treatment with levodopa between 1970 and 1983. Ninety-eight of those started levodopa therapy 2 or more years after symptom onset, while 47 received levodopa within the 1st 2 years of the disease. At the end of follow-up, in December 1985, 49 patients had died. Mortality was 2.5 times higher among patients who delayed initiation of levodopa therapy 2 or more years than among those who initiated the therapy earlier. Age and disease severity were the most significant predictors of survival after initiation of levodopa treatment. The risk of death was 10% higher every year of age increase and was 2 and 4 times higher, respectively, for patients at Hoehn and Yahr stages II and III than for patients at Hoehn and Yahr stage I. When we controlled for the effect of age and disease severity on mortality, the cumulative death probability was no longer significantly higher among patients who delayed levodopa treatment than among patients treated within 2 years from disease onset. As far as mortality is concerned, the results show that the time of levodopa treatment initiation during PD has no influence and the drug can be introduced as soon as indicated by the severity of the disease progression.