title: Influence of genetic, biological and pharmacological factors on levodopa dose in Parkinson's disease.
abstract: OBJECTIVE
  Levodopa is first-line treatment of Parkinson's disease motor symptoms but, dose response is highly variable. Therefore, the aim of this study was to determine how much levodopa dose could be explained by biological, pharmacological and genetic factors.
  
  
  METHODS
  A total of 224 Parkinson's disease patients were genotyped for SV2C and SLC6A3 polymorphisms by allelic discrimination assays. Comedication, demographic and clinical data were also assessed.
  
  
  RESULTS
  All variables with p < 0.20 were included in a multiple regression analysis for dose prediction. The final model explained 23% of dose variation (F = 11.54; p < 0.000001).
  
  
  CONCLUSIONS
  Although a good prediction model was obtained, it still needs to be tested in an independent sample to be validated.
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Altmann
authors.affiliation: Serviço de Neurologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Artur F
authors.initials: AF
authors.lastname: Schumacher-Schuh
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Mariana
authors.initials: M
authors.lastname: Rieck
authors.affiliation: Departamento de Estatística, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Sidia M
authors.initials: SM
authors.lastname: Callegari-Jacques
authors.affiliation: Serviço de Neurologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Carlos R M
authors.initials: CR
authors.lastname: Rieder
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Mara H
authors.initials: MH
authors.lastname: Hutz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010300:Parkinson Disease / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology; D020641:Polymorphism, Single Nucleotide; D012737:Sex Factors
chemical_list: D000978:Antiparkinson Agents; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; C585899:SV2C protein, human; D007980:Levodopa
keywords: Parkinson's disease; algorithm; dopamine transporter; levodopa; pharmacogenetics; synaptic vesicle isoform C