Hypersensitivity myocarditis associated with ephedra use

Heart Toxicity Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 4 of 5

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 approximately seven herbs: Four traditional Chinese medicine herbs - Don quai (Angelica sinensis), Jin bu huan (Lycopodium serratum), Thundergod vine or lei gong teng (Tripterygium wilfordii Hook F), and Ting kung teng (Erycibe henryi prain); one an Ayruvedic herb - Aswagandha, (Withania somnifera); and two North American herbs - blue cohosh (Caulophyllum thalictroides), and Yohimbe (Pausinystalia johimbe). Aconitum and Ephedra species are no longer sold in the United States. The DS included, but are not limited to five DS - bitter orange, caffeine, certain energy drinks, nitric oxide products, and a calming product. Six additional DS are no longer sold. Licorice was the food related to heart problems.

CONCLUSION

The online "Toxic Table" forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity. It may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.

Clozapine-induced hypersensitivity myocarditis presenting as sudden cardiac death

Hypersensitivity myocarditis is a rare but serious adverse effect of clozapine, a commonly used psychiatric drug. We report the case of sudden cardiac death from clozapine-induced hypersensitivity myocarditis diagnosed at autopsy. A 54-year-old Caucasian male on clozapine therapy for bipolar disorder presented with a sudden onset of shortness of breath. Laboratory studies were significant for elevated N-terminal prohormone of brain natriuretic peptide. During his hospital stay, the patient died of sudden cardiac arrest from ventricular tachycardia. The autopsy revealed hypersensitivity myocarditis, which usually occurs in the first 4 weeks after the initiation of clozapine. A 4-week monitoring protocol, including laboratory assessment of troponin and C-reactive protein, may assist in the early diagnosis of this potentially fatal condition.

ESC Study Group of Sports Cardiology Position Paper on adverse cardiovascular effects of doping in athletes

The use of doping substances and methods is extensive not only among elite athletes, but also among amateur and recreational athletes. Many types of drugs are used by athletes to enhance performance, to reduce anxiety, to increase muscle mass, to reduce weight or to mask the use of other drugs during testing. However, the abuse of doping substances and methods has been associated with the occurrence of numerous health side-effects. The adverse effects depend on the type of the consumed drug, as well as the amount and duration of intake and the sensitivity of the body, since there is a large inter-individual variability in responses to a drug. Usually the doses used in sports are much higher than those used for therapeutic purposes and the use of several drugs in combination is frequent, leading to higher risk of side-effects. Among biomedical side-effects of doping, the cardiovascular ones are the most deleterious. Myocardial infarction, hyperlipidemia, hypertension, thrombosis, arrythmogenesis, heart failure and sudden cardiac death have been noted following drug abuse. This paper reviews the literature on the adverse cardiovascular effects after abuse of prohibited substances and methods in athletes, aiming to inform physicians, trainers and athletes and to discourage individuals from using drugs during sports.

Drug-Induced Thrombosis—Experimental, Clinical, and Mechanistic Considerations

Awareness of the dangers of drug-induced thrombosis has recently been heightened and led to demand for improved testing methodology. For example, reports indicating that some selective inhibitors of cyclooxygenase-2 (COX-2) increase the risk of myocardial infarction and atherothrombotic events caused the withdrawal of rofecoxib from global markets and the issuance of warnings concerning the usage of other COX-2 inhibitors. Drugs may exert a prothrombotic state by a variety of mechanisms–those affecting the vessel wall, the blood flow, and/or different blood constituents. Our review serves as an update to that of Gerhard Zbinden published in 1976 by presenting recently acquired data that more fully elucidate the different mechanisms by which drugs are believed to induce thrombogenic effects and discussing new methods used to detect these without losing sight of the classical pathology of thrombosis. We offer correlations between experimental findings and clinical data and conclude that, because drugs may induce a prothrombotic state by a variety of mechanisms, they should be tested for these using appropriate experimental methods and animal models.

Quantitative evaluation of drug-induced microvascular constriction in mice kidney using a novel tool for 3D geometrical analysis of ex vivo organ vasculature

The analysis of organ vasculature, and more specifically organ microvasculature, carries special importance for toxicological sciences, and especially for evaluation of drug-induced vascular toxicity. This field presents a special challenge in nonclinical drug safety assessments since there are currently no reliable microvascular toxicity biomarkers. Therefore, we aimed to systematically investigate the use of microvascular 3D geometrical analysis of corrosion casts for evaluation of drug-induced vascular toxicity, utilizing a novel image investigation tool that allows full 3D-quantified geometrical analysis of the entire vascular tree structure. Vascular casts of kidneys from control and low- and high-dose ephedrine/caffeine-treated mice were scanned by a micro CT, and images were processed and analyzed using the Vasculomics™ platform. All evaluations were performed on the kidney cortex. Treatment resulted in a significant and dose-related reduction in overall microvessel density throughout the kidney cortex. This effect was most pronounced for vessels with diameters between 25 µm and 35 µm, and affected mostly vessels located in the superficial part of the kidney cortex. The use of 3D analysis tools in drug-induced vascular toxicity studies allows for very high resolution and characterization of drug effects on the microvasculature and can be used as a valuable tool in drug safety assessments.

Identification and determination of synthetic pharmaceuticals as adulterants in eight common herbal weight loss supplements

Background:

Adulterated herbal weight loss products with containing undeclared synthetic drugs are common and responsible for many serious health damages.

Objectives:

The purpose of the study was to determine five synthetic adulterants in eight common herbal weight loss supplements, which are currently sold in Iran markets, to verify their presence in supplements, without mentioning on the labels.

Materials and Methods:

Eight common herbal weight loss samples were obtained from the Iran pharmaceutical market after advertising in the Persian language on satellite channels and internet. Five pharmacological classes of drugs used for weight loss, namely sibutramine, phenolphthalein, phenytoin, bumetanide and rimonabant, were investigated and quantified by GC-MS for the first three and LC-MS for the last two medications.

Results:

The most undeclared ingredients, which were illegally added include sibutramine, phenolphthalein, bumetanide, and phenytoin in the original super slim, herbaceous essence, super slim green lean, and fat loss, supplements, respectively. Rimonabant was not found. Caffeine, pseudoephedrine, theobromine and amfepramone were also found in the supplements using GC-MS assay.

Conclusions:

Adulterated synthetic substances were detected in the herbal weight loss products. Health care professionals should make people aware of the risks of taking herbal weight-loss supplements.

Characteristics of patients with advanced heart failure having eosinophilic infiltration of the myocardium in the recent era

Eosinophilic infiltration of the myocardium is occasionally observed as an incidental histological finding in endomyocardial biopsy specimens before heart transplantation (HTx) as well as in explanted heart obtained at the time of HTx. However, the indications for HTx in these patients have not yet been fully established. We investigated the pre-HTx characteristics of the recipients with myocardial eosinophilic infiltration in the explanted heart and diagnosed as hypersensitivity myocarditis (HSM) (21 among 761 recipients, 2.8%). Dobutamine, a common cause of HSM, was administered to 12 patients (57%). Ten patients (47.6%) were on milrinone and 4 (19.0%) were on ventricular assist devices. Post-transplant survival of HSM patients was comparable to that of patients transplanted for active myocarditis or other cause of heart failure. In conclusion, myocardial eosinophilic infiltration is associated with multiple medications in patients with advanced heart failure; however, it does not affect the post-transplant prognosis.

Evidence-based toxicity evaluation and scheduling of Chinese herbal medicines

ETHNOPHARMACOLOGICAL RELEVANCE

While there is an increasing number of toxicity report cases and toxicological studies on Chinese herbal medicines, the guidelines for toxicity evaluation and scheduling of Chinese herbal medicines are lacking.

AIM

The aim of this study was to review the current literature on potentially toxic Chinese herbal medicines, and to develop a scheduling platform which will inform an evidence-based regulatory framework for these medicines in the community.

MATERIALS AND METHODS

The Australian and Chinese regulations were used as a starting point to compile a list of potentially toxic herbs. Systematic literature searches of botanical and pharmaceutical Latin name, English and Chinese names and suspected toxic chemicals were conducted on Medline, PubMed and Chinese CNKI databases.

RESULTS

Seventy-four Chinese herbal medicines were identified and five of them were selected for detailed study. Preclinical and clinical data were summarised at six levels. Based on the evaluation criteria, which included risk-benefit analysis, severity of toxic effects and clinical and preclinical data, four regulatory classes were proposed: Prohibited for medicinal usage, which are those with high toxicity and can lead to injury or death, e.g., aristolochia; Restricted for medicinal usage, e.g., aconite, asarum, and ephedra; Required warning label, e.g., coltsfoot; and Over-the-counter herbs for those herbs with a safe toxicity profile.

CONCLUSION

Chinese herbal medicines should be scheduled based on a set of evaluation criteria, to ensure their safe use and to satisfy the need for access to the herbs. The current Chinese and Australian regulation of Chinese herbal medicines should be updated to restrict the access of some potentially toxic herbs to Chinese medicine practitioners who are qualified through registration.

An Evaluation of Selected Herbal Reference Texts and Comparison to Published Reports of Adverse Herbal Events

OBJECTIVE

There has been a recent proliferation of medical reference texts intended to guide practitioners whose patients use herbal therapies. We systematically assessed six herbal reference texts to evaluate the information they contain on herbal toxicity.

METHODS

We selected six major herbal references published from 1996 to 2000 to evaluate the adequacy of their toxicological information in light of published adverse events. To identify herbs most relevant to toxicology, we reviewed herbal-related calls to our regional California Poison Control System, San Francisco division (CPCS-SF) in 1998 and identified the 12 herbs (defined as botanical dietary supplements) most frequently involved in these CPCS-SF referrals. We searched Medline (1966 to 2000) to identify published reports of adverse effects potentially related to these same 12 herbs. We scored each herbal reference text on the basis of information inclusiveness for the target 12 herbs, with a maximal overall score of 3.

RESULTS

The herbs, identified on the basis of CPCS-SF call frequency were: St John's wort, ma huang, echinacea, guarana, ginkgo, ginseng, valerian, tea tree oil, goldenseal, arnica, yohimbe and kava kava. The overall herbal reference scores ranged from 2.2 to 0.4 (median 1.1). The Natural Medicines Comprehensive Database received the highest overall score and was the most complete and useful reference source. All of the references, however, lacked sufficient information on management of herbal medicine overdose, and several had incorrect overdose management guidelines that could negatively impact patient care.

CONCLUSION

Current herbal reference texts do not contain sufficient information for the assessment and management of adverse health effects of botanical therapies.

Myocarditis at Post-Mortem Examination: A Forensic Perspective

Myocarditis is an uncommon cause of death but its myriad clinical presentations, young target population, diverse etiologies and potential to cause sudden unexpected death warrant its review. Myocarditis has been defined as myocardial necrosis and/or degeneration in the presence of an inflammatory infiltrate adjacent to the damaged myocytes. The type of predominant inflammatory cell present may assist with elucidating its pathoetiology. Ancillary testing as an adjunct to routine histopathological examination, such as immunohistochemical or immunofluorescence staining or detection of viral nucleic acid are of debatable diagnostic use in either the biopsy or autopsy setting. Myocarditis may clinically and/or histologically mimic other disease entities such as acute or organizing myocardial infarction, or hematological malignancy. There are no macroscopic pathognomonic features suggestive of myocarditis, thus in cases of unexplained sudden death it is vital to sample the heart extensively to rule out myocarditis. It is important to recognize that myocarditis may be an incidental finding in an autopsy. To attribute the cause of death to myocarditis, all relevant case findings including scene investigation, autopsy and ancillary testing including toxicology should be assessed.

Uncharted waters: rare and unclassified cardiomyopathies characterized on cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) has undergone considerable technology advances in recent years, so that it is now entering into mainstream cardiac imaging practice. In particular, CMR is proving to be a valuable imaging tool in the detection, morphological assessment and functional assessment of cardiomyopathies. Although our understanding of this broad group of heart disorders continues to expand, it is an evolving group of entities, with the rarer cardiomyopathies remaining poorly understood or even unclassified. In this review, we describe the clinical and pathophysiological aspects of several of the rare/unclassified cardiomyopathies and their appearance on CMR.

Association between consumption of Herbalife nutritional supplements and acute hepatotoxicity

BACKGROUND/AIMS

Nutritional supplements are frequently considered to be harmless but indiscriminate use of unlabelled ingredients may lead to significant adverse reactions.

METHODS

In 2004, identification of four index cases of acute hepatitis associated with Herbalife intake led to a ministry of health investigation in all Israeli hospitals. Twelve patients with acute idiopathic liver injury in association with consumption of Herbalife products were investigated.

RESULTS

Eleven of the patients were females, aged 49.5+/-13.4 y. One patient had stage I primary biliary cirrhosis and another had hepatitis B. Acute liver injury was diagnosed after 11.9+/-11.1 months of initiation of Herbalife consumption. Liver biopsies demonstrated active hepatitis, portal inflammation rich with eosinophils, ductular reaction and parenchymal inflammation with peri-central accentuation. One patient developed sub-fulminant and two fulminant episodes of hepatic failure. Hepatitis resolved in eleven patients, while one patient succumbed to complications following liver transplantation. Three patients resumed consumption of Herbalife products following normalization of liver enzymes, resulting in a second bout of hepatitis.

CONCLUSIONS

An association between intake of Herbalife products and acute hepatitis was identified in Israel. We call for prospective evaluation of Herbalife products for possible hepatotoxicity. Until then, caution should be exercised by consumers, especially among individuals suffering from underlying liver disease.

Myocarditis

Viruses are the most common cause of myocarditis in economically advanced countries.

Enteroviruses and adenoviruses are the most common etiologic agents.

Viral myocarditis is a triphasic process. Phase 1 is the period of active viral replication in the myocardium during which the symptoms of myocardial damage range from none to cardiogenic shock. If the disease process continues, it enters phase 2, which is characterized by autoimmunity triggered by viral and myocardial proteins. Heart failure often appears for the first time in phase 2. Phase 3, dilated cardiomyopathy, is the end result in some patients. Diagnostic procedures and treatment should be tailored to the phase of disease.

Viral myocarditis is a significant cause of dilated cardiomyopathy, as proved by the frequent presence of viral genomic material in the myocardium, and by improvement in ventricular function by immunomodulatory therapy.

Myocarditis of any etiology usually presents with heart failure, but the second most common presentation is ventricular arrhythmia. As a result, myocarditis is one of the most common causes of sudden death in young people and others without preexisting structural heart disease.

Myocarditis can be definitively diagnosed by endomyocardial biopsy. However, it is clear that existing criteria for the histologic diagnosis need to be refined, and that a variety of molecular markers in the myocardium and the circulation can be used to establish the diagnosis.

Treatment of myocarditis has been generally disappointing. Accurate staging of the disease will undoubtedly improve treatment in the future. It is clear that immunosuppression and immunomodulation are effective in some patients, especially during phase 2, but may not be as useful in phases 1 and 3. Since myocarditis is often selflimited, bridging and recovery therapy with circulatory assistance may be effective. Prevention by immunization or receptor blocking strategies is under development.

Giant cell myocarditis is an unusually fulminant form of the disease that progresses rapidly to heart failure or sudden death. Rapid onset of disease in young people, especially those with other autoimmune manifestations, accompanied by heart failure or ventricular arrhythmias, suggests giant cell myocarditis.

Peripartum cardiomyopathy in economically developed countries is usually the result of myocarditis.

Top-10 list of herbal and supplemental medicines used by cosmetic patients: what the plastic surgeon needs to know

BACKGROUND

Widespread use of herbal medications/supplements among the presurgical population may have a negative effect on perioperative patient care. Thus, the authors' goal was to identify the prevalence of such use in a cosmetic surgery patient population compared with use among the general public; to assess physician awareness of proper management of these herbal medications/supplements; and to review the literature to provide rational strategies for managing perioperative patients taking these remedies.

METHODS

To assess patient (n = 100) and general public (n = 100) usage rates, open-ended lists of (1) the most common herbal medications/supplements and (2) homeopathic treatments were compiled. Board-certified plastic surgeons (n = 20) were then given the same list of herbs/supplements and surveyed on their awareness of these treatments and perioperative side effects.

RESULTS

The usage rate for cosmetic versus public surveys for herbal medicines/supplements was 55 percent versus 24 percent (p < 0.001), with 35 percent versus 8 percent (p < 0.001) engaging in homeopathic practices, respectively. Cosmetic patients' top four herbal/supplements of usage were chondroitin (18 percent), ephedra (18 percent), echinacea (14 percent), and glucosamine (10 percent). The top four used by the general public were echinacea (8 percent), garlic (6 percent), ginseng (4 percent), and ginger (4 percent). The physician survey demonstrated awareness of 54 percent of the listed supplements/herbal medicines, 85 percent of which were not suggested to be discontinued preoperatively, with only ephedra achieving 100 percent physician discontinuation preoperatively.

CONCLUSIONS

Herbal medicines and supplements displayed greater prevalence in the cosmetic surgery population than in the population at large. Furthermore, side effects and potential complications warrant addressing these remedies as pharmaceuticals rather than as safe and "natural." Thus, a descriptive "top-10" list with perioperative recommendations was compiled for the plastic surgeon.

LACK OF HINOKITIOL (BETA-THUJAPLICIN) CARCINOGENICITY IN F344/DuCrj RATS

Chronic toxicity and carcinogenicity of hinokitiol (beta-thujaplicin), used as an antibiotic and fungicidal agent of a food additive, was examined in both sexes of F344/DuCrj (F344) rats. In this chronic toxicity study, groups of 10 rats of each sex were given a diet containing hinokitiol at doses of 0, 0.005, 0.015 and 0.05% for 52 weeks. No treatment-related adverse effects were noted in the survival rate, general condition, body weights, food consumption, urinalysis, hematology and clinical chemistry. Slight but significant elevation of spleen and liver weights was noted in both sexes given 0.05% hinokitiol, along with an increase in hemosiderin deposits in male spleens, related to chelator binding of iron, together with slight centrilobular hypertrophy of male hepatocytes. However, these alterations were negligible and not toxicologically significant. In the carcinogenicity study, groups of 50 female and 50 male rats were given a diet containing hinokitiol at doses of 0, 0.005, 0.015 and 0.05% (excluding 0.005% in females). No treatment-related changes in survival rate, general condition, body weight, food consumption, hematology and organ weights were noted. Detailed histopathological examination revealed no treatment-related increase in the incidences of any neoplastic lesions. The results demonstrate that hinokitiol is not carcinogenic in F344 rats of either sex.

The potential impact of the use of homeopathic and herbal remedies on monitoring the safety of prescription products

The purpose of this paper is to explore the possibility that adverse reactions and drug interactions arising from the use of homeopathic and herbal medicines could lead to confusion when adverse reactions to conventional medicines are reported. An extensive literature review was conducted on the occurrence of adverse reactions and drug interactions following the use of homeopathic or herbal remedies, and the potential for these to confound adverse event reporting to conventional medicines considered. The survey demonstrates the potential for herbal remedies and homeopathic products, to produce adverse drug reactions or drug interactions, and shows the scope for potential for confusion with those arising from conventional medicines. There is a need for greater awareness that adverse reactions apparently due to a conventional medicine, might in reality be due to a herbal medicine or a drug interaction between a herbal medicine and a conventional drug, particularly when a health professional is unaware of the extent of a patient's self-medication with alternative therapies.

Dilated cardiomyopathy and acute liver injury associated with combined use of ephedra, gamma-hydroxybutyrate, and anabolic steroids

Anabolic-androgenic steroids are synthetic derivatives of testosterone that some athletes have used to enhance muscle mass and improve their athletic performance. Ephedrine is a potent sympathomimetic agent that can lead to cardiomyopathy similar to that seen with catecholamine excess. Adverse cardiovascular events attributed to anabolic steroid and ephedra use, such as arrhythmias, myocardial infarction, cardiomyopathy, and sudden death, are rarely reported. Bodybuilders have used gamma-hydroxybutyrate, a potent secretagogue of growth hormone, to promote muscle development. Although dilated cardiomyopathy is a known complication of excess growth hormone levels, it has not been associated with use of gamma-hydroxybutyrate. A healthy 40-year-old man was admitted to our hospital for new-onset congestive heart failure and severe acute hepatitis that developed several months after he began using anabolic-androgenic steroids, ephedra, and gamma-hydroxybutyrate supplements. Analysis with an objective causality assessment scale revealed a probable adverse drug reaction between the patient's use of anabolic steroids, ephedra, and gamma-hydroxybutyrate and the development of his cardiomyopathy and acute liver injury.

Aqueous extract of ma huang suppresses neuropeptide Y expression in food-deprived rat hypothalamus

Ma huang, the dried plant stem of ephedra intermedia Schrenk et C.A., contains an ephedrine-type alkaloid and has been used for weight loss. Neuropeptide Y (NPY), a 36-amino acid peptide, is concentrated in the hypothalamus and stimulates feeding desire. In this study, the effect of ma huang on the expressions of NPY in the hypothalamus of rats was investigated using immunohistochemistry. Food-deprivation enhanced the NPY expression in the hypothalamus. ma huang suppressed the food-deprivation-induced enhancement of NPY expression. Present results suggest that ma huang curbs the food desire by suppressing the NPY expression under food-deprivation conditions.

Is there an association between ephedra and heart failure? a case series

BACKGROUND

Ephedra is a sympathomimetic commonly used for the purposes of athletic performance enhancement and weight loss. It is known to be associated with gastrointestinal and psychiatric manifestations. We report here on 6 cases of dilated cardiomyopathy associated with ephedra use.

METHODS AND RESULTS

Over a period of 18 months, 6 patients attending our outpatient department with new onset heart failure were noted to have exposure to ephedra. The case record was reviewed and detailed clinical and echocardiographic data were extracted. All 6 patients (4 males) had left ventricular dysfunction at presentation (mean ejection fraction 20 +/- 5%) and were treated with conventional heart failure pharmacotherapy. All patients discontinued ephedra use as advised. New York Heart Association class improved from class III in 5 patients (class II in 1 patient) to class I, within a median of 6 months (range 3-96). Ejection fraction improved to a mean of 47 +/- 6%.

CONCLUSIONS

Ephedra may be associated with left ventricular systolic dysfunction. Withdrawal of this agent, in conjunction with proven pharmacotherapy, results in a significant improvement in functional status and left ventricular ejection fraction. We recommend specific enquiry into the use of over-the-counter supplements, particularly ephedra and its derivatives, when being evaluated with heart failure symptoms. These cases illustrate the potential risk of ephedra and provide additional support for the recent decision to ban this supplement.

Drug bioactivation, covalent binding to target proteins and toxicity relevance

A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targets of reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.

Ma huang associated acute liver failure requiring liver transplantation

An ever increasing number of herbal remedies are recognized as potentially hepatotoxic. We report a case of fulminant hepatic failure requiring liver transplantation associated with the use of Ma huang, a traditional Chinese remedy containing ephedrine-type alkaloids. The literature surrounding the potential liver toxicities of Ma huang is reviewed and the proposed pathogenetic mechanisms are critically examined.

Safety of ephedra: lessons learned

The safe use of ephedra represents the best possible outcome of a convergence of variables, some with troubling potential outcomes. Commercially used ephedra and its products is prepared from Ephedra spp. and as such is subject to a variety of influences (including differences in species and strain; growth, harvest and storage conditions) all of which may influence the content of constituents (which may, in turn, affect the absorption, distribution, and metabolism of active constituents) and taken together, influences the net pharmacological effect. Further, as a natural substance with an easily perceived and desirable (i.e. weight-loss) pharmacological effect, ephedra is also susceptible to a variety of adulterants, both economic and efficacious. All of the foregoing represent potential for misadventure before ephedra even reaches the consumer. The consumer introduces a constellation of variables as well, including, but not limited to, acute and chronic diseases, inborn errors in metabolism, simultaneous use of prescription and over-the-counter drugs, dietary supplements, alcohol, illicit substances and certain foods (e.g. chocolate, caffeinated drinks), all or some of which may exert synergistic, additive or even antagonistic influences on the desired physiologic outcome. The foregoing not withstanding, the majority of the published nonclinical and clinical studies, and history of use, support the safety of ephedra at the proposed use levels. However, the reports of adverse events submitted to FDA raise concern about the risk associated with ephedra without establishing a direct causal relationship. Given the foregoing, how best can a decision on safety be made? Should the question actually be "can ephedra be as toxic as reported?"

Herbal bioactivation: the good, the bad and the ugly

It has been well established that the formation of reactive metabolites of drugs is associated with drug toxicity. Similarly, there are accumulating data suggesting the role of the formation of reactive metabolites/intermediates through bioactivation in herbal toxicity and carcinogenicity. It has been hypothesized that the resultant reactive metabolites following herbal bioactivation covalently bind to cellular proteins and DNA, leading to toxicity via multiple mechanisms such as direct cytotoxicity, oncogene activation, and hypersensitivity reactions. This is exemplified by aristolochic acids present in Aristolochia spp, undergoing reduction of the nitro group by hepatic cytochrome P450 (CYP1A1/2) or peroxidases in extrahepatic tissues to reactive cyclic nitrenium ion. The latter was capable of reacting with DNA and proteins, resulting in activation of H-ras oncogene, gene mutation and finally carcinogenesis. Other examples are pulegone present in essential oils from many mint species; and teucrin A, a diterpenoid found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming diets. Extensive pulegone metabolism generated p-cresol that was a glutathione depletory, and the furan ring of the diterpenoids in germander was oxidized by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase. On the other hand, some herbal/dietary constituents were shown to form reactive intermediates capable of irreversibly inhibiting various CYPs. The resultant metabolites lead to CYP inactivation by chemical modification of the heme, the apoprotein, or both as a result of covalent binding of modified heme to the apoprotein. Some examples include bergamottin, a furanocoumarin of grapefruit juice; capsaicin from chili peppers; glabridin, an isoflavan from licorice root; isothiocyanates found in all cruciferous vegetables; oleuropein rich in olive oil; dially sulfone found in garlic; and resveratrol, a constituent of red wine. CYPs have been known to metabolize more than 95% therapeutic drugs and activate a number of procarcinogens as well. Therefore, mechanism-based inhibition of CYPs may provide an explanation for some reported herb-drug interactions and chemopreventive activity of herbs. Due to the wide use and easy availability of herbal medicines, there is increasing concern about herbal toxicity. The safety and quality of herbal medicine should be ensured through greater research, pharmacovigilance, greater regulatory control and better communication between patients and health professionals.

Acute Myocardial Infarction Induced by Ephedrine Alkaloids

A 45-year-old woman was hospitalized to rule out acute myocardial infarction after coming to the emergency department with a complaint of substernal chest pressure. Her initial electrocardiogram indicated normal sinus rhythm with T-wave inversion and nonspecific ST changes suggestive of possible ischemia. She had no medical problems and took no prescription drugs. Further evaluation revealed that for approximately 4 years she had been taking Metabolife 356 preparations--a source of ephedrine alkaloids--for weight loss, and that she was at low risk for atherosclerotic coronary artery disease. Due to elevated cardiac markers, cardiac catheterization was performed, which revealed no atherosclerosis in the coronary arteries. The patient's acute myocardial infarction was attributed to coronary artery vasospasm induced by ephedrine alkaloids. Clinicians should be aware of the growing evidence that supports life-threatening cardiovascular toxicities associated with these substances.

Stroke associated with sympathomimetics contained in over-the-counter cough and cold drugs

BACKGROUND AND PURPOSE

Phenylpropanolamine (PPA) and pseudoephedrine are sympathomimetics contained in over-the-counter cold preparations. A case-control study linked PPA use with hemorrhagic stroke in women. Twenty-two patients with stroke associated with use of these drugs are described.

METHODS

In a consecutive stroke registry since 1988, 22 patients had stroke associated with over-the-counter sympathomimetics. Sympathomimetic dosage and type, time interval until stroke onset, and neuroimaging findings are described.

RESULTS

Ten male and 12 female patients were included. Intracerebral hemorrhage occurred in 17 patients, subarachnoid hemorrhage in 4, and ischemic stroke in 1. Stroke was associated with PPA use in 16 patients (dose 75 to 675 mg), with pseudoephedrine in 4 (dose 60 to 300 mg), and with others administered by the nasal route in 2 (oxymetazoline and phenylephrine). Stroke occurred after a single dose in 17 patients and after daily use during several days in 5. The interval between drug exposure and clinical onset varied from 30 minutes to 24 hours. Stroke occurred after recommended doses of PPA (50 to 75 mg) in 32% and pseudoephedrine (60 mg) in 50% of patients. Eight patients had acute hypertension at stroke onset. Cerebral angiography was normal in 8 cases and showed diffuse vasospasm or beading in 10 patients.

CONCLUSIONS

Stroke related to over-the-counter sympathomimetics was associated with acute hypertension and/or vasospasm or angiitis mechanisms, most related to the use of PPA; however, stroke also occurred with the use of other sympathomimetics, particularly pseudoephedrine. Although stroke complications occurred when doses were used that were higher than recommended doses, apparently there is also a stroke risk when these agents are taken properly.

The role of chemical fingerprinting: application to Ephedra

Ephedra sinica, known as Ma Huang, is one of the oldest medicinal herbs in Traditional Chinese Medicine (TCM). Preparations, namely teas, of E. sinica have been used for over 5000 years as a stimulant and as an antiasthmatic. In the West, extracts of E. sinica, E. intermedia or E. equisetina are most commonly used in dietary supplements as a stimulant and to promote weight loss. More than 50 species of Ephedra are native to both hemispheres, but the detection of ephedrine alkaloids has been limited to species in Eurasia. Currently, methods exist to quantitate the ephedrine alkaloids in extracts of plant material or dietary supplements, but the methods are not able to verify the extract is of an Ephedra species. Reverse phase high performance liquid chromatography with photodiode array detection was applied for the chemical fingerprinting of the Ephedra species. Two regions of comparison were determined in the chromatograms at 320 nm. The series of peaks between 52 and 64 min confirms an Ephedra species is being analyzed. The aforementioned peaks also could distinguish between Ephedra species from Eurasia, North America and South America. Peaks at ca. 57 and 59 min were isolated and determined to be two new compounds, 4-(2-eicosyloxycarbonyl-vinyl)-benzoic acid and 4-(2-docosyloxycarbonyl-vinyl)-benzoic acid respectively. Authentication of ground plant material as Ephedra can be achieved by this chemical fingerprinting method.

The peri-operative implications of herbal medicines

An increasing number of patients are taking herbal medicines such as echinacea, garlic, ginkgo biloba, ginseng, St John's Wort, valerian, ephedra, kava, grapefruit juice and ginger. Although these herbal medications are considered 'natural' products that may have some benefits, adverse effects such as increased bleeding tendencies and drug interactions are associated with their use. Surgeons and anaesthetists may be unaware of their patients' use of these medications because it is common for patients not to disclose their use of this form of medication, and both surgeons and anaesthetists often fail to enquire about their use. Anaesthetists and surgeons must be familiar with the effects of herbal medicines and should specifically enquire about the use of herbal medicines during pre-operative assessment. Currently available data suggest that all herbal medicines should be ceased 2 weeks before surgery.

Informed decision-making on sympathomimetic use in sport and health

The International Olympic Committee, the World Anti-Doping Agency, and International Sport Federations have banned and restricted the use of many stimulants including prescription and over-the-counter medications and dietary supplements. In addition to elite athletes, people of all ages use stimulants in attempts to improve athletic performance, alter body composition, and increase levels of energy. Here we introduce a seven-stage model designed to facilitate informed decision-making by individuals taking or thinking of taking stimulants for sport, health, and/or appearance reasons. We review for amphetamines, over-the counter sympathomimetics, and caffeine their performance-enhancing and performance-degrading effects, health benefits and mechanisms of action, medical side effects, and legal, ethical, safety, and financial implications.

Benefits, adverse effects and drug interactions of herbal therapies with cardiovascular effects

Because the use of herbal therapies in the U.S. is escalating, it is essential to be aware of clinical and adverse effects, doses and potential drug-herb interactions. A consumer poll in 1998 indicated that one-third of respondents use botanical remedies, and nearly one in five taking prescription medications also used herbs, high-dose dietary supplements or both. An estimated 15 million adults are at risk for potential adverse interactions involving prescription medications and herbs or vitamin supplements, yet most practicing physicians have little knowledge of herbal remedies or their effects. Herbal products are marketed without the proof of efficacy and safety that the Food and Drug Administration (FDA) requires of drugs. The Dietary Supplement and Health Education Act of 1994 allocates responsibility to manufacturers for ensuring safety and efficacy with no specific requirements to submit documentation. Manufacturers may state a product's physiologic effects but may not make claims for the treatment or cure of specific diseases. Consumers and practitioners have little information about product safety, contraindications, interactions or effectiveness and are reliant on manufacturers to provide accurate labeling. Recently, the growing number of foods with herbs has raised concerns at the FDA, which requires evidence that food additives are safe. Considering that the growing appeal of herbal remedies is likely to continue, physicians, particularly cardiologists, must become familiar with the available cardiovascular information on herbs. This review highlights the existing data on the efficacy, adverse effects and interactions for herbal therapies that impact on the cardiovascular system.

Adverse cardiovascular events temporally associated with ma huang, an herbal source of ephedrine

OBJECTIVE

To evaluate possible cardiovascular toxic effects associated with use of dietary supplements containing ma huang, an herbal source of ephedrine.

METHODS

We reviewed the comprehensive database Adverse Reaction Monitoring System of the Food and Drug Administration, which included clinical records, investigative reports, and autopsy reports related to ma huang use. The main outcome measurements were stroke, myocardial infarction, and sudden death.

RESULTS

From 1995 to 1997, 926 cases of possible ma huang toxicity were reported to the Food and Drug Administration. In 37 patients (23 women and 14 men with a mean +/- SD age of 43 +/- 13 years), use of ma huang was temporally related to stroke (in 16), myocardial infarction (in 10), or sudden death (in 11). Autopsies performed in 7 of the 11 patients who experienced sudden death showed a normal heart in 1, coronary atherosclerosis in 3, and cardiomyopathies in 3. In 36 of the 37 patients, use of ma huang was reported to be within the manufacturers' dosing guidelines.

CONCLUSIONS

Analysis of the 37 patients indicates the following findings: (1) ma huang use is temporally related to stroke, myocardial infarction, and sudden death; (2) underlying heart or vascular disease is not a prerequisite for ma huang-related adverse events; and (3) the cardiovascular toxic effects associated with ma huang were not limited to massive doses. Although the pathogenesis of the cardiac toxic effects of ma huang remains incompletely defined, available observational and circumstantial evidence indicates that use of the substance may be associated with serious medical complications.

Acute necrotizing eosinophilic myocarditis successfully treated by high dose methylprednisolone

Acute necrotizing eosinophilic myocarditis is the most severe form of eosinophilic myocarditis, or hypersensitivity myocarditis, and is characterized by rapidly progressive congestive heart failure followed by fulminant clinical deterioration that is nearly always fatal. A 55-year-old previously healthy patient with acute necrotizing eosinophilic myocarditis was diagnosed by early myocardial biopsy and successfully treated with corticosteroids. Throughout his hospitalization, the eosinophil count in the peripheral blood remained normal (56-201/mm3). Early stage corticosteroid therapy can have dramatic effects in acute necrotizing eosinophilic myocarditis and early diagnosis by endomyocardial biopsy is recommended.

Suspected caffeine and ephedrine toxicosis resulting from ingestion of an herbal supplement containing guarana and ma huang in dogs: 47 cases (1997-1999)

OBJECTIVE

To describe the clinical signs following ingestion of an herbal supplement containing guarana and ma huang in dogs, estimate minimum dose at which clinical signs of toxicosis and death were reported, and evaluate treatment options.

DESIGN

Retrospective study.

ANIMALS

47 dogs with evidence of ingestion of an herbal supplement containing primarily guarana and ma huang.

PROCEDURE

Records of dogs that had ingested an herbal supplement containing ma huang and guarana between July 1997 and October 1999 were retrieved from the National Animal Poison Control Center database. Data were retrieved and reviewed regarding signalment, dose ingested, clinical signs, laboratory test results, treatment, and final outcome. Cases were assessed by staff veterinarians as toxicosis or suspected toxicosis on the basis of strength of evidence supporting a diagnosis.

RESULTS

Most dogs (80%) developed clinical signs of toxicosis within 8 hours of ingestion, and clinical signs persisted for up to 48 hours. Hyperactivity, tremors, seizures, and behavior changes were reported in 83% of dogs; other signs included vomiting (47%), tachycardia (30%), and hyperthermia (28%). Seventeen percent of the dogs died or were euthanatized. Estimated doses of guarana and ma huang ranged from 4.4 to 296.2 mg/kg (1.98 to 133.2 mg/lb) and 1.3 to 88.9 mg/kg (0.58 to 40.0 mg/lb) of body weight, respectively; minimum dose at which death was reported was 19.1 mg of guarana/kg (8.7 mg/lb) and 5.8 mg of ma huang/kg (2.6 mg/lb).

CONCLUSIONS AND CLINICAL RELEVANCE

Accidental ingestion of herbal supplements containing primarily guarana and ma huang in dogs can lead to a potentially lethal condition that may require prompt detoxification and supportive treatment for several days. Most dogs recovered with supportive treatment.

Use, understanding, and beliefs about complementary and alternative medicines among emergency department patients

OBJECTIVES

To describe the extent of complementary and alternative medicine (CAM) use among emergency department (ED) patients, to evaluate patients' understanding of CAMs, and to determine gender differences in beliefs about CAMs.

METHODS

This study was a convenience sampling of patients seen in an urban ED. Patient demographics were recorded. A questionnaire was administered that assessed patients' knowledge and use of CAMs. Patients were also asked about their beliefs on safety, medication interactions, and conveying information about these substances to their physicians.

RESULTS

A total of 350 ED patients were included in the study; 87% had heard of at least one of the CAMs. There was no difference between genders or races concerning knowledge about CAMs. The most commonly known CAMs were ginseng (75%), ginkgo biloba (55%), eucalyptus (58%), and St. John's wort (57%). Forty-three percent of the responders had used CAMs at some time and 24% were presently using CAMs. The most commonly used CAMs were ginseng (13%), St. John's wort (6%), and ginkgo biloba (9%). All CAMs were considered to be safe by 16% of the patients. Only 67% would tell their doctors they were using CAMs. Females were more likely than males to believe that CAMs do not interact with other medications (15% vs 7%, difference 8%, 95% CI = 2% to 15%).

CONCLUSIONS

Complementary and alternative medicines are familiar to most patients and used by many of them. Despite this, a large percentage of patients would not tell their physicians about their use of alternative medications. Emergency medicine providers should be aware of the commonly used CAMs, and questions about their use should be routinely included in ED exams.

Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids

BACKGROUND

Dietary supplements that contain ephedra alkaloids (sometimes called ma huang) are widely promoted and used in the United States as a means of losing weight and increasing energy. In the light of recently reported adverse events related to use of these products, the Food and Drug Administration (FDA) has proposed limits on the dose and duration of use of such supplements. The FDA requested an independent review of reports of adverse events related to the use of supplements that contained ephedra alkaloids to assess causation and to estimate the level of risk the use of these supplements poses to consumers.

METHODS

We reviewed 140 reports of adverse events related to the use of dietary supplements containing ephedra alkaloids that were submitted to the FDA between June 1, 1997, and March 31, 1999. A standardized rating system for assessing causation was applied to each adverse event.

RESULTS

Thirty-one percent of cases were considered to be definitely or probably related to the use of supplements containing ephedra alkaloids, and 31 percent were deemed to be possibly related. Among the adverse events that were deemed definitely, probably, or possibly related to the use of supplements containing ephedra alkaloids, 47 percent involved cardiovascular symptoms and 18 percent involved the central nervous system. Hypertension was the single most frequent adverse effect (17 reports), followed by palpitations, tachycardia, or both (13); stroke (10); and seizures (7). Ten events resulted in death, and 13 events produced permanent disability, representing 26 percent of the definite, probable, and possible cases.

CONCLUSIONS

The use of dietary supplements that contain ephedra alkaloids may pose a health risk to some persons. These findings indicate the need for a better understanding of individual susceptibility to the adverse effects of such dietary supplements.