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Journal ArticleDOI

A case report of atrial fibrillation potentially induced by hydroxycut: a multicomponent dietary weight loss supplement devoid of sympathomimetic amines.

08 Apr 2010-Journal of Pharmacy Practice (SAGE Publications)-Vol. 23, Iss: 3, pp 245-249
TL;DR: Patients at risk of developing AF should avoid dietary supplements containing E GCG until more information on the adverse effects of EGCG is known, given the serious risks associated with AF.
Abstract: Multicomponent dietary weight loss supplements comprise the single largest segment of herbal preparations available to the public. As a result of limited de novo regulatory oversight, supplement-related adverse events are underreported secondary to the lack of adequate pharmacodynamic, pharmacokinetic, and clinical data. Here we report the case of an obese 63-year-old caucasian female with a 2-day history of symptomatic paroxysmal atrial fibrillation (AF) with rapid ventricular response following a 2-week course of therapy with hydroxycut, a multicomponent dietary weight loss supplement devoid of sympathomimetic amines. Upon presentation, the patient received 2 doses of intravenous diltiazem, was loaded with intravenous digoxin, and spontaneously converted to normal sinus rhythm 36 hours following her last dose of the product. Epigallocatechin (EGCG), a principal ingredient in the hydroxycut preparation is the suspected causative component. EGCG blocks the atrial-specific KCNA5 potassium channel. Loss of ...
Citations
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Journal ArticleDOI
TL;DR: The history, safety, and efficacy of caffeine-containing dietary supplements in the United States and Canada is reviewed to address some of the pharmacologic and pharmaceutical issues that distinguish caffeine- containing dietary supplement formulations from traditional caffeine-contained beverages.

69 citations

Journal ArticleDOI
TL;DR: The prevalence of dietary supplement use in Navy and Marine Corps personnel was considerably higher than reported in civilian investigations for almost all types of dietary supplements, although similar to most other military services.

61 citations


Cites background from "A case report of atrial fibrillatio..."

  • ...Hydroxycut was again reformulated without these substances, but the older formulations still appear to be available.(88,89) Some cases of AEs continue to appear even with the newer formulation....

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Journal ArticleDOI
TL;DR: Information gaps in DS information and AE reporting were identified and a centralized AE reporting system could serve to identify potentially harmful DS for further evaluation.
Abstract: AB Purpose: Dietary supplement (DS) use among US military personnel is widespread. Many consume several different DS with multiple ingredients one or more times each week, representing a potential public health concern. The overall purpose of the study was to assess the knowledge and behaviors of health professionals and physicians regarding patterns of DS use and possible adverse events (AE) associated with DS use. We also determined how providers address the issue of DS with patients and evaluated provider knowledge regarding reporting systems. Methods: Two prospective, cross-sectional, web-based questionnaires were administered. First, health care providers who accessed the Natural Medicines Comprehensive Database to gather evidenced-based information on DS and herbal products were queried. Second, physicians who had graduated from the Uniformed Services University were sent a web-based questionnaire regarding DS knowledge, AE knowledge and reporting, and communication with patients about DS. The frequencies of responses were evaluated. Results: Although 60% of the military physicians who responded to the questionnaires believed they had observed AE in association with a DS, only 18% actually reported them. Three of four physician respondents (approximately 73%) did not know how or where to report AE associated with DS. The majority of physicians (66%) routinely asked most of their patients about DS use, and 65% did not have a reliable source of information for herbal and DS products. Conclusions: Information gaps in DS information and AE reporting were identified. A centralized AE reporting system could serve to identify potentially harmful DS for further evaluation. Health professionals need to remain vigilant for AE associated with DS use and better informed on how to report these events.

43 citations

Journal ArticleDOI
TL;DR: The online “Toxic Table” forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity, and may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.
Abstract: Background: The purpose of this review was to create an online research summary table of heart toxicity case reports related to dietary supplements (DS; includes herbs). Methods: Documented PubMed case reports of DS appearing to contribute to heart-related problems were used to create a “Toxic Table” that summarized the research (1966 to April, 2016, and cross-referencing). Keywords included “herb,” “dietary supplement,” and cardiac terms. Case reports were excluded if they were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm (e.g. suicide), excess dose (except vitamins/minerals), drugs or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. The spectrum of heart toxicities included hypertension, hypotension, hypokalemia, bradycardia, tachycardia, arrhythmia, ventricular fibrillation, heart attack, cardiac arrest, heart failure, and death. Results: Heart related problems were associated with a...

29 citations

Journal Article
TL;DR: Use of herbal medicine for weight reduction is not always safe, and for some herbal medicine the risk is sufficient to shift the risk-benefit balance against the use that medicine.
Abstract: BACKGROUND: Obesity is a common health problem in both developed and developing countries. There are many unconventional therapies, including herbal medicine, to treat this condition. Some people believe that herbal medicines are safe. This case and review is about adverse complication of treating obesity with some herbal medicine. CASE REPORT: A 19 year old male with sever obesity (120 kg) used green tea (15 cups of green tea per day) and an intensive dietary regimen to lose weight. He lost 30 kg after 2 months. At that time, one day after usual exercise he suddenly lost consciousness due to left ventricular fibrillation. CONCLUSION: Use of herbal medicine for weight reduction is not always safe. Moreover, for some herbal medicine the risk is sufficient to shift the risk–benefit balance against the use that medicine. Keywords: Herbal Medicine, Sudden Death, Complication, Obesity

12 citations

References
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Journal ArticleDOI
TL;DR: It was shown that the ADR probability scale has consensual, content, and concurrent validity and may be applicable to postmarketing drug surveillance.
Abstract: The estimation of the probability that a drug caused an adverse clinical event is usually based on clinical judgment. Lack of a method for establishing causality generates large between-raters and within-raters variability in assessment. Using the conventional categories and definitions of definite, probable, possible, and doubtful adverse drug reactions (ADRs), the between-raters agreement of two physicians and four pharmacists who independently assessed 63 randomly selected alleged ADRs was 38% to 63%, kappa (k, a chance-corrected index of agreement) varied from 0.21 to 0.40, and the intraclass correlation coefficient of reliability (R[est]) was 0.49. Six (testing) and 22 wk (retesting) later the same observers independently reanalyzed the 63 cases by assigning a weighted score (ADR probability scale) to each of the components that must be considered in establishing causal associations between drug(s) and adverse events (e.g., temporal sequence). The cases were randomized to minimize the influence of learning. The event was assigned a probability category from the total score. The between-raters reliability (range: percent agreement = 83% to 92%; κ = 0.69 to 0.86; r = 0.91 to 0.95; R(est) = 0.92) and within-raters reliability (range: percent agreement = 80% to 97%; κ = 0.64 to 0.95; r = 0.91 to 0.98) improved (p < 0.001). The between-raters reliability was maintained on retesting (range: r = 0.84 to 0.94; R(est) = 0.87). The between-raters reliability of three attending physicians who independently assessed 28 other prospectively collected cases of alleged ADRs was very high (range: r = 0.76 to 0.87; R(est) = 0.80). It was also shown that the ADR probability scale has consensual, content, and concurrent validity. This systematic method offers a sensitive way to monitor ADRs and may be applicable to postmarketing drug surveillance. Clinical Pharmacology and Therapeutics (1981) 30, 239–245; doi:10.1038/clpt.1981.154

9,840 citations

Journal ArticleDOI
TL;DR: This first report of Kv1.5 loss-of-function channelopathy establishes KCNA5 mutation as a novel risk factor for repolarization deficiency and atrial fibrillation.
Abstract: Atrial fibrillation is a rhythm disorder characterized by chaotic electrical activity of cardiac atria. Predisposing to stroke and heart failure, this common condition is increasingly recognized as a heritable disorder. To identify genetic defects conferring disease susceptibility, patients with idiopathic atrial fibrillation, lacking traditional risk factors, were evaluated. Genomic DNA scanning revealed a nonsense mutation in KCNA5 that encodes Kv1.5, a voltage-gated potassium channel expressed in human atria. The heterozygous E375X mutation, present in a familial case of atrial fibrillation and absent in 540 unrelated control individuals, introduced a premature stop codon disrupting the Kv1.5 channel protein. The truncation eliminated the S4-S6 voltage sensor, pore region and C-terminus, preserving the N-terminus and S1-S3 transmembrane domains that secure tetrameric subunit assembly. Heterologously expressed recombinant E375X mutant failed to generate the ultrarapid delayed rectifier current I(Kur) vital for atrial repolarization and exerted a dominant-negative effect on wild-type current. Loss of channel function translated into action potential prolongation and early after-depolarization in human atrial myocytes, increasing vulnerability to stress-provoked triggered activity. The pathogenic link between compromised Kv1.5 function and susceptibility to atrial fibrillation was verified, at the organism level, in a murine model. Rescue of the genetic defect was achieved by aminoglycoside-induced translational read-through of the E375X premature stop codon, restoring channel function. This first report of Kv1.5 loss-of-function channelopathy establishes KCNA5 mutation as a novel risk factor for repolarization deficiency and atrial fibrillation.

462 citations

Journal ArticleDOI
17 Sep 2003-JAMA
TL;DR: Consumers may be misled by vendors' claims that herbal products can treat, prevent, diagnose, or cure specific diseases, despite regulations prohibiting such statements.
Abstract: ContextPassage of the Dietary Supplement Health and Education Act in 1994 restricted the Food and Drug Administration's control over dietary supplements, leading to enormous growth in their promotion. The Internet is often used by consumers as a source of information on such therapies.ObjectiveTo assess the information presented and indications claimed on the Internet for the 8 best-selling herbal products.Data SourcesWe searched the Internet using the 5 most commonly used search engines. For each, we entered the names of the 8 most widely used herbal supplements (ginkgo biloba, St John's wort, echinacea, ginseng, garlic, saw palmetto, kava kava, and valerian root). We analyzed the health content of all Web sites listed on the first page of the search results.Study SelectionWe analyzed all accessible, English-language Web sites that pertained to oral herbal supplements. A total of 522 Web sites were identified; of these, 443 sites met inclusion criteria for the analysis.Data ExtractionThe nature of the Web site (retail or nonretail), whether it was a sponsored link, and all references, indications, claims, and disclaimers were recorded. Two reviewers independently categorized medical claims as disease or nondisease according to Food and Drug Administration criteria.Data SynthesisAmong 443 Web sites, 338 (76%) were retail sites either selling product or directly linked to a vendor. A total of 273 (81%) of the 338 retail Web sites made 1 or more health claims; of these, 149 (55%) claimed to treat, prevent, diagnose, or cure specific diseases. More than half (153/292; 52%) of sites with a health claim omitted the standard federal disclaimer. Nonretail sites were more likely than retail sites to include literature references, although only 52 (12%) of the 443 Web sites provided referenced information without a link to a distributor or vendor.ConclusionsConsumers may be misled by vendors' claims that herbal products can treat, prevent, diagnose, or cure specific diseases, despite regulations prohibiting such statements. Physicians should be aware of this widespread and easily accessible information. More effective regulation is required to put this class of therapeutics on the same evidence-based footing as other medicinal products.

272 citations


"A case report of atrial fibrillatio..." refers background in this paper

  • ...Despite a noticeable lack of data supporting the clinical efficacy of most dietary supplements, 81% of dietary supplement manufacturers advertised unsupported health claims with 55% of these claims overtly stating that their products prevented, diagnosed, treated, or cured diseases.(4,5) The current regulatory environment combined with patient and provider unfamiliarity about the appropriate role for herbal medicine leads to a wide array of supplement-related adverse events, with ephedra containing weight loss supplements (eg, Metabolife 356, Hydroxycut RFA) being among the most notable preparations....

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Journal ArticleDOI
TL;DR: The efficacy of optimal doses of HCA‐SX alone and in combination with niacin‐bound chromium and a standardized Gymnema sylvestre extract on weight loss in moderately obese subjects was evaluated by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and excretion of urinary fat metabolites.
Abstract: Aim: The efficacy of optimal doses of highly bioavailable (–)-hydroxycitric acid (HCA-SX) alone and in combination with niacin-bound chromium (NBC) and a standardized Gymnema sylvestre extract (GSE) on weight loss in moderately obese subjects was evaluated by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and excretion of urinary fat metabolites. HCA-SX has been shown to reduce appetite, inhibit fat synthesis and decrease body weight without stimulating the central nervous system. NBC has demonstrated its ability to maintain healthy insulin levels, while GSE has been shown to regulate weight loss and blood sugar levels. Methods: A randomized, double-blind, placebo-controlled human study was conducted in Elluru, India for 8weeks in 60 moderately obese subjects (ages 21–50, BMI >26kg/m 2 ). Subjects were randomly divided into three groups. Group A was administered HCA-SX 4667mg, group B was administered a combination of HCA-SX 4667mg, NBC 4mg and GSE 400mg, while group C was given placebo daily in three equally divided doses 30–60min before meals. All subjects received a 2000kcal diet/day and participated in supervised walking. Results: At the end of 8weeks, body weight and BMI decreased by 5–6% in both groups A and B. Food intake, total cholesterol, low-density lipoproteins, triglycerides and serum leptin levels were significantly reduced in both groups, while high-density lipoprotein levels and excretion of urinary fat metabolites increased in both groups. A marginal or non-significant effect was observed in all parameters in group C. Conclusion: The present study shows that optimal doses of HCA-SX and, to a greater degree, the combination of HCASX, NBC and GSE can serve as an effective and safe weight-loss formula that can facilitate a reduction in excess body weight and BMI, while promoting healthy blood lipid levels.

182 citations

Journal ArticleDOI
TL;DR: It is reported that overexpression of the Kv1.5 channel gene (KCNA5) in human PASMC and other cell lines produced a 15-pS single channel current and a large whole cell current that was sensitive to 4-aminopyridine, and novel SNPs in the promoter and translated regions of KCNA5 are present in IPAH patients.
Abstract: The pore-forming α-subunit, Kv1.5, forms functional voltage-gated K+ (Kv) channels in human pulmonary artery smooth muscle cells (PASMC) and plays an important role in regulating membrane potential...

157 citations

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Can Hydroxycut affect sperm count?

Thus, causal relationship between hydroxycut and AF in this patient is probable.