Purpose: Levodopa dose per kilogram body weight is reported to be a significant factor for dyskinesia in Parkinson's disease. We have investigated this hypothesis in data from the studies comparing ropinirole versus levodopa as the initial therapy.
Methods: Data from the ropinirole versus levodopa studies 056 and REAL-PET in early Parkinson's disease were pooled and manipulated to calculate levodopa dose per kilogram body weight. Logistic regression analysis was performed to investigate significant variables for the development of dyskinesia. Only the patients on levodopa monotherapy or with ropinirole were analyzed.
Results: Analysis of levodopa therapy patients revealed that dyskinetic patients had received significantly higher absolute levodopa dose and levodopa dose per kilogram body weight. Logistic regression revealed that the most significant factor was the higher levodopa dose per kilogram body weight, P = 0.005, odds ratio 1.078, 95% CI 1.023-1.135; younger age was the second factor -P = 0.026. Variables of gender, absolute levodopa dose, weight, disease duration and initial motor Unified Parkinson's disease rating score were not significant.
Conclusion: Higher levodopa dose per kilogram body weight is an independently significant factor for developing dyskinesia. This relationship should be considered in treatment of Parkinson's disease patients aiming to prevent and manage dyskinesia.