Absence of QTc-Interval–Prolonging or Hemodynamic Effects of a Single Dose of Bitter-Orange Extract in Healthy Subjects
Article first published online: 16 JAN 2012
2005 Pharmacotherapy Publications Inc.
Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy
Volume 25, Issue 12, pages 1719–1724, December 2005
How to Cite
Min, B., Cios, D., Kluger, J. and White, C. M. (2005), Absence of QTc-Interval–Prolonging or Hemodynamic Effects of a Single Dose of Bitter-Orange Extract in Healthy Subjects. Pharmacotherapy, 25: 1719–1724. doi: 10.1592/phco.2005.25.12.1719
- Issue published online: 16 JAN 2012
- Article first published online: 16 JAN 2012
- Manuscript received March 30, 2005; Accepted for publication in final form August 15, 2005
- QTc interval;
- bitter-orange dried-fruit extract;
- hemodynamic effects;
- electrocardiographic effects
Study 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.
Design. Randomized, double-blind, placebo-controlled, crossover study.
Setting. University of Connecticut, Storrs Campus.
Subjects. Eighteen healthy volunteers aged 18 years or older.
Intervention. 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.
Measurements and Main 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).
Conclusion. 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.