Electrocardiographic effects of an Ephedra-Free, multicomponent weight-loss supplement in healthy volunteers.
OBJECTIVE
Metabolife 356, an ephedra-containing weight-loss product, substantially increases the corrected QT (QTc) interval. Metabolife Ephedra Free, a similar supplement, contains caffeine and extracts of green tea, garcinia cambogia, and yerba mate. Its electrocardiographic (ECG) effects are not known. Therefore, we sought to determine the effect of this supplement on the QTc interval.


METHODS
Randomized, double-blind, placebo-controlled, crossover study.


METHODS
University of Connecticut, Storrs Campus.


METHODS
Twenty healthy volunteers. Intervention. A single capsule containing half the normal recommended dose of Metabolife Ephedra Free or matching placebo was administered in crossover fashion, with a 7-day washout period between treatments.


RESULTS
Baseline and three postdose ECG measurements were obtained, and QTc intervals were measured over a 5-hour study period. No significant differences in the QTc interval or other ECG variables were observed between the Metabolife Ephedra Free and placebo groups.


CONCLUSIONS
At half the recommended single dose, Metabolife Ephedra Free does not affect the QTc interval or other ECG variables over 5 hours. Dose-response studies and studies of longer duration should be conducted.
Min
Bokyung
B
School of Pharmacy, University of Connecticut, Storrs, 06102, USA.
McBride
Brian F
BF
Kardas
Michael J
MJ
Ismali
Agron
A
Sinha
Vinnita
V
Kluger
Jeffrey
J
White
C Michael
CM
D000328:Adult; D019440:Anti-Obesity Agents / Q000008:administration & dosage / Q000009:adverse effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004562:Electrocardiography; D029789:Ephedra; D005260:Female; D006801:Humans; D008297:Male; D008517:Phytotherapy; D028321:Plant Preparations / Q000008:administration & dosage / Q000009:adverse effects
D019440:Anti-Obesity Agents; D028321:Plant Preparations