title: Absence of QTc-interval-prolonging or hemodynamic effects of a single dose of bitter-orange extract in healthy subjects.
abstract: OBJECTIVE
  To evaluate the hemodynamic and electrocardiographic effects of a single dose of commercially available bitter-orange dried-fruit extract, which is increasingly being used in dietary supplements.
  
  
  METHODS
  Randomized, double-blind, placebo-controlled, crossover study.
  
  
  METHODS
  University of Connecticut, Storrs Campus.
  
  
  METHODS
  Eighteen healthy volunteers aged 18 years or older.
  
  
  METHODS
  Subjects were given either placebo or bitter-orange dried-fruit extract (450 mg standardized to 27 mg of m- or p-synephrine) in phase 1. The opposite treatment was given during phase 2 after a washout period of at least 7 days.
  
  
  RESULTS
  The rate-corrected QT (QTc) interval and blood pressure were measured before dosing and at 1, 3, 5, and 8 hours after dosing. Mean+/-SD values of the maximum postdose values were compared between groups. Subjects receiving bitter-orange extract versus those receiving placebo had similar postdose QTc intervals (402+/-29 vs 403+/-24 msec, p=0.653), systolic blood pressure (114+/-10 vs 115+/-8 mm Hg, p=0.686) and diastolic blood pressure (68+/-9 vs 68+/-8, p=0.879).
  
  
  CONCLUSIONS
  Bitter-orange dried-fruit extract standardized to m- or p-synephrine 27 mg did not significantly alter the QTc interval or blood pressure after a single dose was administered. Future studies are necessary to ensure the safety of this herbal product with multiple doses.
authors.affiliation: School of Pharmacy, University of Connecticut, Storrs, and Division of Cardiology, Hartford Hospital, Hartford, Connecticut 06102-5037, USA.
authors.forename: Bokyung
authors.initials: B
authors.lastname: Min
authors.forename: Deborah
authors.initials: D
authors.lastname: Cios
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Kluger
authors.forename: C Michael
authors.initials: CM
authors.lastname: White
mesh_terms: D000328:Adult; D019440:Anti-Obesity Agents / Q000009:adverse effects*; D002957:Citrus / Q000737:chemistry*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D005638:Fruit; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D010936:Plant Extracts / Q000009:adverse effects
chemical_list: D019440:Anti-Obesity Agents; D010936:Plant Extracts