Multiple Dosing of Ephedra-Free Dietary Supplements: Hemodynamic, Electrocardiographic, and Bacterial Contamination Effects

Department of Dietetics and Nutrition, College of Health Professions University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Clinical Pharmacology &#38 Therapeutics (Impact Factor: 7.9). 12/2012; 93(3). DOI: 10.1038/clpt.2012.241
Source: PubMed


Four popular ephedra-free dietary supplements were evaluated for their effects on heart rate (HR), blood pressure (BP), and electrocardiographic (ECG) parameters. Twelve healthy men participated in a study randomized for product sequence, with a 21-day washout period between supplement-administration phases. Throughout the study, Holter monitors were used to assess ECG and HR activity. BP was assessed automatically on multiple occasions. The supplements were ingested three times daily for 3 days. Caffeine content, microbial load, and serum caffeine concentrations were determined. Mean systolic (SBP) and diastolic BP (DBP) readings showed significant increases relative to baseline (10.8 ± 2.5 and 5.3 ± 3.1 mm Hg, respectively; P < 0.05). All supplements significantly increased HR and decreased bradycardia runs; abnormal atrial/ventricular events were frequently noted. Gastrointestinal and sympathomimetic symptoms were also common. Two supplements were heavily contaminated with Bacillus species. In light of these findings, the use of ephedra-free dietary supplements should be discouraged in individuals with hypertension, diabetes, or other cardiovascular diseases.Clinical Pharmacology & Therapeutics (2013); advance online publication 30 January 2013. doi:10.1038/clpt.2012.241.

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Available from: Ashraf A Khan, Apr 01, 2014
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