title: Risk factors for levodopa-induced dyskinesias in Parkinson's disease.
abstract: To identify putative risk factors for levodopa-induced dyskinesias we studied the effect of several clinical variables on the occurrence of dyskinesias in a series of 168 consecutive patients with Parkinson's disease treated for at least 6 months with levodopa. Of these, 108 (64%) developed dyskinesias after a mean duration of levodopa treatment of 51.4 +/- 43.3 months. Patients tended to suffer dyskinesias on the side of the body first affected by Parkinson's disease. The overall probability of developing dyskinesias increased with levodopa treatment duration, about 10% per year during the first 7 years. Univariate and multivariate logistic regression analysis identified the age at onset of Parkinson's disease (OR 0.923; 95% CI 0.883-0.964) and the initial levodopa dose (mean dose of the first 6 months of treatment; OR 1.004; 95% CI 1.002-1.006) as the main independent predictors. Survival curves showed that onset of Parkinson's disease at age 50 years or before (logrank, P < 0.05) and initial levodopa treatment with more than 600 mg/day (logrank, P < 0.05) were associated with a higher risk for the appearance of dyskinesias.
authors.affiliation: Servicio de Neurología, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Grandas
authors.forename: M L
authors.initials: ML
authors.lastname: Galiano
authors.forename: C
authors.initials: C
authors.lastname: Tabernero
mesh_terms: D017668:Age of Onset; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004409:Dyskinesia, Drug-Induced / Q000503:physiopathology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010300:Parkinson Disease / Q000188:drug therapy* / Q000453:epidemiology; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D007980:Levodopa