Absence of QTc-interval-prolonging or hemodynamic effects of a single dose of bitter-orange extract in healthy subjects.
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.
Min
Bokyung
B
School of Pharmacy, University of Connecticut, Storrs, and Division of Cardiology, Hartford Hospital, Hartford, Connecticut 06102-5037, USA.
Cios
Deborah
D
Kluger
Jeffrey
J
White
C Michael
CM
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
D019440:Anti-Obesity Agents; D010936:Plant Extracts