title: Caffeine in Parkinson's disease: a pilot open-label, dose-escalation study.
abstract: BACKGROUND
  Epidemiologic studies consistently find an inverse association between caffeine use and PD. Numerous explanations exist, but are difficult to evaluate as caffeine's symptomatic effect and tolerability in PD are unknown.
  
  
  METHODS
  We designed an open-label, 6-week dose-escalation study of caffeine to establish dose tolerability and evaluate potential motor/nonmotor benefits. Caffeine was started at 200 mg daily and was increased to a maximum of 1,000 mg.
  
  
  RESULTS
  Of 25 subjects, 20 tolerated 200 mg, 17 tolerated 400 mg, 7 tolerated 800 mg, and 3 tolerated 1,000 mg. The most common adverse events were gastrointestinal discomfort, anxiety, and worsening/emerging tremor. At 400 mg daily, we found potential improvements in motor manifestations and somnolence (UPDRS III: -4.5 ± 4.6, P = 0.003; Epworth: -2.0 ± 3.0, P = 0.015).
  
  
  CONCLUSIONS
  Maximum dose tolerability for caffeine in PD appears to be 100 to 200 mg BID. We found pilot preliminary evidence that caffeine may improve some motor and nonmotor aspects of PD, which must be confirmed in longer term, placebo-controlled, clinical trials.
authors.affiliation: Department of Neurology, McGill University, Montreal General Hospital, Montreal, Quebec, Canada.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Altman
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Postuma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D002110:Caffeine