title: Dihydropyridine calcium channel blockers and the progression of parkinsonism.
abstract: OBJECTIVE
  A study was undertaken to test the association between dihydropyridine calcium channel blocker use and the time to important milestones of disease progression among patients with parkinsonism.
  
  
  METHODS
  Data were obtained from Ontario's health care administrative databases. Within a cohort of hypertensive individuals older than 65 years who developed parkinsonism, we examined the effect of the length of exposure to less brain-penetrant dihydropyridines (amlodipine) and more brain-penetrant dihydropyridines (eg, nifedipine, felodipine) on parkinsonism milestones as measured by time to requiring drug treatment for parkinsonism, nursing home admission, and death.
  
  
  RESULTS
  Among 4,733 hypertensive individuals with parkinsonism, longer treatment with any dihydropyridine was associated with a decreased risk of each of the 3 outcomes. There was no difference, however, between amlodipine (adjusted hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.42-0.50 for initiation of drug treatment; HR, 0.68; 95% CI, 0.63-0.73 for application for nursing home admission; and HR, 0.75; 95% CI, 0.70-0.80 for death) and nonamlodipine dihydropyridines (adjusted HRs [95% CIs], 0.45 [0.39-0.53], 0.74 [0.67-0.81], and 0.74 [0.64-0.85] for the 3 milestones, respectively).
  
  
  CONCLUSIONS
  We found no specific beneficial effect of treatment with brain-penetrant dihydropyridines on delaying parkinsonism progression milestones. Dihydropyridine calcium channel blockers are unlikely to have a clinically significant effect on the course of parkinsonism, particularly Parkinson disease, in the doses used to treat hypertension.
authors.affiliation: Division of Neurology, Toronto Western Hospital, and University of Toronto, Toronto, Ontario, Canada. cmarras@uhnresearch.ca
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.forename: Andrea
authors.initials: A
authors.lastname: Gruneir
authors.forename: Paula
authors.initials: P
authors.lastname: Rochon
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wang
authors.forename: Geoff
authors.initials: G
authors.lastname: Anderson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brotchie
authors.forename: Chaim M
authors.initials: CM
authors.lastname: Bell
authors.forename: Susan
authors.initials: S
authors.lastname: Fox
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D015331:Cohort Studies; D004095:Dihydropyridines / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D008297:Male; D020734:Parkinsonian Disorders / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D002121:Calcium Channel Blockers; D004095:Dihydropyridines; C038806:1,4-dihydropyridine