Acute clenbuterol overdose resulting in supraventricular tachycardia and atrial fibrillation

Adverse events of clenbuterol among athletes: a systematic review of case reports and case series

Clenbuterol is a potent beta-2 agonist widely misused by professional athletes and bodybuilders. Information on clenbuterol associated adverse events is present in case reports and case series, though it may not be readily available. This systematic review aimed to critically evaluate the evidence of adverse events associated with clenbuterol among athletes. The search strategy was in accordance with PRISMA guidelines. Databases such as PubMed, Science Direct, Scopus, and Google Scholar were searched from 1990 to October 2021 to find out the relevant case reports and case series. There were 23 included studies. Using a suitable scale, the included studies' methodological quality analysis was evaluated. In total, 24 athletes experienced adverse events. Oral ingestion of clenbuterol was the most preferred route among them. The daily administered dose of clenbuterol was ranging from 20 µg to 30 mg. Major adverse events experienced by athletes were supraventricular tachycardia, atrial fibrillation, hypotension, chest pain, myocardial injury, myocarditis, myocardial ischemia, myocardial infarction, cardiomyopathy, hepatomegaly, hyperglycemia, and death. The cardiac-related complications were the most commonly occurring adverse events. Clenbuterol is notorious to produce life-threatening adverse events including death. Lack of evidence regarding the performance-enhancing effects of clenbuterol combined with its serious toxicities questions the usefulness of this drug in athletes.

Post-mortem investigation into a death involving doping agents: The case of a body builder

INTRODUCTION

A young male was found dead on the bed of a hotel room. He was expected to take part in a bodybuilding competition the day after. During the site inspection, drugs of different types were found. The next day, an autopsy was performed. The evidence of cardiomegaly with organ congestion involving lung, liver, kidneys, adrenal glands, spleen and brain was confirmed by both the autoptic and the histopathological exam. However, the cause of death needed to be investigated.

METHODS

A thorough toxicological investigation was undertaken by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-high resolution mass spectrometry (LC-HRMS) and liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) on samples of urine, blood and hair.

RESULTS AND DISCUSSION

Clenbuterol, a long-acting selective beta₂ agonist, was found in both blood (1 ng/ml) and urine (1 ng/ml), and evidence of its use was provided by the analysis of the 3-cm hair (25 pg/mg). The main metabolite of drostanolone (2 alpha-methyl-androsterone), an anabolic steroid, was found in the urine (202 ng/ml), where an increased ratio of testosterone/epitestosterone (T/E = 11) emerged. Due to the results of the hair analysis, a long-term use of various anabolic steroids was supposed. The integrated analysis of the results and the absence of other possible causes (such as trauma or cardiac conduction anomalies) led to the identification of the abuse of doping substances as the underlying cause of death.

CONCLUSION

Hair analysis has proven to be crucial in identifying drug misuse and the contributing cause of death.

Review of the Pathophysiologic and Clinical Aspects of Hypokalemia in Children and Young Adults: an Update

This article examines the regulatory function of the skeletal muscle, renal, and adrenergic systems in potassium homeostasis. The pathophysiologic bases of hypokalemia, systematic approach for an early diagnosis, and therapeutic strategy to avert life-threatening complications are highlighted. By promoting skeletal muscle uptake, intense physical exercise (post), severe trauma, and several toxins produce profound hypokalemia. Hypovolemia due to renal and extra-renal fluid losses and ineffective circulation activate secondary aldosteronism causing urinary potassium wasting. In addition to hypokalemic alkalosis, primary aldosteronism causes low-renin hypertension. Non-aldosterone mineralocorticoid activation leading to low-renin and low-aldosterone hypertension occurs in Liddle's syndrome and apparent mineralocorticoid excess. Although there is enzymatic inhibition of cortisol synthesis in congenital adrenal hyperplasia, precursors of aldosterone produce low-renin hypokalemic hypertension. In addition to the glucocorticoid effect, hypercortisolism activates mineralocorticoid receptors in Cushing's syndrome. Genetic mutations involving furosemide-sensitive Na+-K+-2Cl- co-transporters and thiazide-sensitive Na+-Cl- transporters result in (non-hypertensive) salt-wasting nephropathy. Proximal and distal renal tubular acidosis is associated with hypokalemia. Eating disorders causing hypokalemia include bulimia, laxative abuse, and diuretic misuse. Low urinary potassium (<15 mmol/day) and/or low urinary chloride (<20 mol/L) suggest a gastrointestinal pathology. Co-morbidity of hypokalemia with chronic pulmonary and cardiovascular diseases may increase the fatality rate.

Impact of COPD or Asthma on the Risk of Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background:

Respiratory diseases related to chronic pulmonary ventilation dysfunction are mainly composed of chronic obstructive pulmonary disease (COPD) and asthma. Our meta-analysis aimed to illustrate the association of COPD or asthma with risk of atrial fibrillation (AF).

Methods

We systematically searched the databases of the PubMed, Embase, and Cochrane library until December 2021 for studies focusing on the relationship between COPD or asthma and AF risk. Due to the potential heterogeneity across studies, the random-effects model was used to pool the studies.

Results

Our meta-analysis included 14 studies. Based on the random-effects model, the pooled analysis showed that COPD (risk ratio[RR] = 1.74, 95% confidence interval [CI]: 1.70–1.79) and asthma (RR = 1.08, 95% CI: 1.04–1.12) were significantly associated with an increased risk of AF. The results did not change after each study was excluded.

Conclusion

Our current data suggested that COPD or asthma with associated with an increased risk of AF.

Salbutamol-Induced QT Interval Prolongation in a Two-Year-Old Patient

Salbutamol-induced QT interval prolongation is a relatively rare adverse effect of beta2-agonists. We report a case of a two-year-old female patient with no known past medical history, brought by her parents to the ED 30 minutes after ingesting a total dose of 97 mg of salbutamol solution. ECG was done for the patient when she arrived and showed sinus tachycardia with prolonged QTc (509 ms) and normal QRS complex. The patient was admitted to the Pediatric Intensive Care Unit (PICU) with persistent tachycardia and tachypnea in the initial reassessment. ECG was repeated with normal QT interval after IV Mg sulfate. The patient was observed in PICU for 12 hours with serial ECG and venous blood gas (VBG). IV potassium chloride (KCL) infusion started, and serial VBG showed normal potassium and lactate. The patient was doing well in the next six hours, with normal serial ECG, labs, and vital signs.

In conclusion, salbutamol-induced QT prolongation has infrequently been reported in the literature. Although inhaled salbutamol is commonly used in clinical practice, physicians have limited experience with the severe features of its toxicity. Salbutamol is known to cause minimal side effects, which may be under-recognized and progress to serious manifestations such as hypokalemia, QT prolongation, and sudden cardiac death.

Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

A new potentiometric platform: Antibody cross-linked graphene oxide potentiometric immunosensor for clenbuterol determination

An immunosensor is based on the signal measurement obtained upon the reaction of an antibody antigen complex. It plays a significant role in various fields such as environmental analysis, production monitoring, drug detection or screening, veterinary medicine, and animal food. In this study, an antibody crosslinked graphen oxide (GO)-based potentiometric sensor has been developed for fast, simple, and economical detection of clenbuterol. In this context, the photosensitive amino acid bound GO platform is synthesized and used for the preparation of electrode material. Then, polymeric structure is characterized by infrared spectroscopy, and the performance of immunonano platform prepared by potentiometric sensor is evaluated. The effect of pH, response time, selectivity, and sensitivity is investigated. Under the optimized conditions, a simple and rapid method for the determination of clenbuterol from milk sample is established by immuno-potentiometric sensor. The detection limit has found to be 0.87 × 10^-9 mmol L^-1 for this immuno-potentiometric sensor. This immuno-potentiometric sensor has optimum pH at 7.0, a wide linear response (1.0 × 10^-2 to 1.0 × 10^-9 mmol L^-1 ), rapid response time (2 Min) and 36 weeks operational lifetime.

Clenbuterol-Induced Myocarditis: A Case Report

Objective

We present a case of a 22-year-old bodybuilder diagnosed with myocarditis secondary to clenbuterol use.

Results

The patient was primarily managed conservatively by the discontinuation of clenbuterol and the temporary use of dual anti-platelets, beta-blockers and nitrates.

Conclusion

Clenbuterol is a long-acting beta-2 agonist primarily used in veterinary medicine. In recent years, it has been illegally marketed as a weight loss supplement because of its anabolic properties and is popular among fitness enthusiasts. It is our aim to use this case to underscore the adverse effects of this drug with hopes that tighter regulations will be instituted to stem its illegal distribution.

LEARNING POINTS

Clenbuterol is primarily a veterinary drug with bronchodilator and tocolytic properties.It is illegally used as a performance enhancer by athletes and bodybuilders because of its anabolic properties.Clenbuterol misuse can result in myocardial injury.

Clenbuterol: a new toxic substance in paediatrics

A 13-year-old girl presented to the emergency department with acute onset of chest pain, nausea and tremor. The patient denied drug ingestion, and urine toxicology was negative. ECG demonstrated sinus tachycardia, prolonged QTc (541 ms) and ST depression. Laboratory testing demonstrated metabolic acidosis, hypokalaemia, hypophosphataemia and hyperglycaemia. She was commenced on continuous cardiac monitoring and treated with intravenous fluids and electrolyte replacement. Presenting features and laboratory abnormalities resolved within 48 hours. The National Poisons Information Service and Clinical Biochemistry were integral to her management, advising the clinical team on the likeliest aetiology. Five weeks after discharge, urine toxicology, using mass spectrometry, identified clenbuterol. Clenbuterol is an oral β2-agonist with anabolic and lipolytic effects that is misused as a performance and image enhancing drug. Clinicians must be aware of the increasing availability of these drugs and their potential for causing harm in children and adolescents.

Complete Post-mortem Investigations in a Death Involving Clenbuterol After Long-term Abuse

The body of a 61-year-old man was found at his home by his wife, lying on the floor, near the bathroom, around midnight. He was known to be training for bodybuilding, using anabolic steroids. Police investigations revealed the presence of two types of tablets at home, one supposed to contain clenbuterol (0.040 mg) and the other stanozolol (10 mg). Testing the tablets revealed different dosages from what was expected, i.e., 0.073 and 11.5 mg/tablet, for clenbuterol and stanozolol, respectively. External body examination and autopsy, which was performed the next day, revealed generalized organ congestion and lack of any traumatic injury (confirmed by radiology). Cardiomegaly, with a heart weighing 692 g, was obvious. Anatomic pathology tests did not reveal evidence of malformations, but atheromatous plaque was identified in the coronaries during complete histology investigations. Femoral blood, urine, bile, gastric contents and two strands of hair (6 cm) were collected for toxicology. These specimens were submitted to standard analyses, but also to a specific LC-MS-MS method for clenbuterol and stanozolol testing. Clenbuterol was identified in all the tissues, including femoral blood (1.1 ng/mL), urine (7.2 ng/mL), bile (2.4 ng/mL), gastric content (3.2 ng/mL) and hair (23 pg/mg). Stanozolol only tested positive in hair (11 pg/mg). All other analyses were negative, including blood alcohol and drugs of abuse. The pathologists concluded to cardiac insufficiency with support of cardiomegaly, in a context involving repetitive abuse of anabolic drugs. This case indicates that more attention should be paid to clenbuterol, a drug widely used as a stimulant by people who want to lose weight, athletes and bodybuilding practitioners.

Acute Decompensated Heart Failure Secondary to Exogenous Triiodothyronine Use in a Young Non-athlete Weightlifter

Heart failure (HF) is a common cardiovascular disorder and is associated with increased morbidity and mortality. HF is usually detected in the elderly population, in particular, in patients with coronary artery disease, valvular disease, myocarditis, and hypertension. Acute decompensated HF in previously healthy young patients should raise suspicion for other rare etiologies. We report a case of a 28-year-old male presenting with acutely decompensated HF secondary to performance-enhancing drugs (PED). The use of non-regulated, non-approved PED has become a world-wide health problem with patients often unaware of the potentially serious and fatal side effects.

Evaluation of R- (-) and S- (+) Clenbuterol enantiomers during a doping cycle or continuous ingestion of contaminated meat using chiral liquid chromatography by LC-TQ-MS

Clenbuterol is known to improve competition resistance and muscular growth in athletes. Although it is an illegal drug, its use by farmers is widely spread to induce growth of their cattle. Thus, when clenbuterol is found in the urine of an athlete, there is doubt whether it was consumed with doping purposes or if it is due to the consumption of meat from a clenbuterol-fed animal. Previous studies suggest that enantiomeric relationship of clenbuterol may be different according to the intake source. However, the enantiomeric relationship throughout a doping cycle or a continuous intake of contaminated meat has not yet been explored. In this first approximation, our aim was the development and validation of a sensitive and rapid method for the determination of S- (+) and R- (─) clenbuterol enantiomers to be used in a controlled study in rats fed for one week with contaminated meat or simulating a doping cycle. Enantiomers were measured using liquid chromatography coupled to mass spectrometry with a triple quadrupole analyzer (LC-TQ-MS) and were separated on an AGP Chiralpak column. The method was fully validated following the VICH (Veterinary International Conference on Harmonization guidelines) and was linear in the range of 12.5-800 pg/mL with a correlation coefficient of ≥0.98 for each enantiomer, and with a limit of quantitation and detection (LOQ and LOD) of 12.5 pg/mL and 6.5 pg/mL, respectively, for both enantiomers. The application of this method pointed out the shift of the enantiomeric relationship in urine from rats during the first five days of the doping cycle compared to those fed with contaminated meat. This finding can be of substantial importance in further doping studies.

Chomping at the Bit: A Descriptive Report on Pediatric Clenbuterol Ingestion

INTRODUCTION

Clenbuterol hydrochloride is a selective beta-2 adrenergic agonist with uses in both humans and animals. Ingestions occurring within the United States are generally due to incidental ingestion of a veterinary product, use as a cutting agent for illicit substances, or illegal use for performance-enhancing purposes.

CASE REPORT

A four-and-a-half year-old male presented approximately two-and-a-half hours after an accidental ingestion of an unknown quantity of clenbuterol. Initial laboratory results and electrocardiogram were remarkable for hyperglycemia, hypokalemia, and hypophosphatemia, with an electrocardiogram demonstrating sinus tachycardia. Heart rate ranged from 126 to 147 beats per minute while other vitals remained within normal limits. The patient was observed for 24 hours and discharged with normalized vital signs, laboratory results, and electrocardiogram.

DISCUSSION

Clenbuterol hydrochloride is a beta-agonist with high potency, extended half-life, and bioavailability of 70% to 80%. Tachycardia occurs due to beta-1 receptor stimulation, as well as a homeostatic reflex to peripheral vasodilation. Hyperglycemia is not uncommon in exposures and intracellular shifting of potassium causes hypokalemia. Treatment is primarily supportive in nature, with hemodynamic management representing the primary focus of initial triage.

High-Content Assay Multiplexing for Muscle Toxicity Screening in Human-Induced Pluripotent Stem Cell-Derived Skeletal Myoblasts

Skeletal muscle-associated toxicity is an underresearched area in the field of high-throughput toxicity screening; hence, the potential adverse effects of drugs and chemicals on skeletal muscle are largely unknown. Novel organotypic microphysiological in vitro models are being developed to replicate the contractile function of skeletal muscle; however, the throughput and a need for specialized equipment may limit the utility of these tissue chip models for screening. In addition, recent developments in stem cell biology have resulted in the generation of induced pluripotent stem cell (iPSC)-derived skeletal myoblasts that enable high-throughput in vitro screening. This study set out to develop a high-throughput multiplexed assay using iPSC-derived skeletal myoblasts that can be used as a first-pass screen to assess the potential for chemicals to affect skeletal muscle. We found that cytotoxicity and cytoskeletal integrity are most useful and reproducible assays for the skeletal myoblasts when evaluating overall cellular health or gauging disruptions in actin polymerization following 24 h of exposure. Both assays are based on high-content imaging and quantitative image processing to derive quantitative phenotypes. Both assays showed good to excellent assay robustness and reproducibility measured by interplate and interday replicability, coefficients of variation of negative controls, and Z'-factors for positive control chemicals. Concentration response assessment of muscle-related toxicants showed specificity of the observed effects compared to the general cytotoxicity. Overall, this study establishes a high-throughput multiplexed assay using skeletal myoblasts that may be used for screening and prioritization of chemicals for more complex tissue chip-based and in vivo evaluation.

Abuse of Prescription Drugs in the Context of Novel Psychoactive Substances (NPS): A Systematic Review

Recently, a range of prescription and over-the-counter drugs have been reportedly used as Novel Psychoactive Substances (NPS), due to their potential for abuse resulting from their high dosage/idiosyncratic methods of self-administration. This paper provides a systematic review of the topic, focusing on a range of medications which have emerged as being used recreationally, either on their own or in combination with NPS. Among gabapentinoids, pregabalin may present with higher addictive liability levels than gabapentin, with pregabalin being mostly identified in the context of opioid, polydrug intake. For antidepressants, their dopaminergic, stimulant-like, bupropion activities may explain their recreational value and diversion from the therapeutic intended use. In some vulnerable clients, a high dosage of venlafaxine (‘baby ecstasy’) is ingested for recreational purposes, whilst the occurrence of a clinically-relevant withdrawal syndrome may be a significant issue for all venlafaxine-treated patients. Considering second generation antipsychotics, olanzapine appears to be ingested at very large dosages as an ‘ideal trip terminator’, whilst the immediate-release quetiapine formulation may possess proper abuse liability levels. Within the image- and performance- enhancing drugs (IPEDs) group, the beta-2 agonist clenbuterol (‘size zero pill’) is reported to be self-administered for aggressive slimming purposes. Finally, high/very high dosage ingestion of the antidiarrhoeal loperamide has shown recent increasing levels of popularity due to its central recreational, anti-withdrawal, opiatergic effects. The emerging abuse of prescription drugs within the context of a rapidly modifying drug scenario represents a challenge for psychiatry, public health and drug-control policies.

Collaborative Public Health Investigation of Clenbuterol-Adulterated Heroin Outbreak-Richmond, Virginia, March-April 2015

CONTEXT

In March 2015, the Virginia Department of Health (VDH) was alerted by the Virginia Poison Center of a 6-patient cluster treated for severe clinical presentations after using heroin. Patients' symptoms were atypical for heroin use, and concern existed that patients were exposed to heroin that had been adulterated with or replaced by another substance.

OBJECTIVE

To understand the extent and characterization of the outbreak and implement response measures to prevent further cases. The purpose of this report is to highlight the collaborative nature of a public health investigation among a diverse group of stakeholders.

DESIGN

Active surveillance and retrospective case finding.

SETTING

Richmond metro area community and hospitals.

PARTICIPANTS

Regional poison centers, the Division of Consolidated Laboratory Services, the Department of Behavioral Health and Developmental Services, community partners, local law enforcement, and multiple VDH divisions.

INTERVENTION

Outbreak investigation, communication to public health professionals, clinicians, and the community, and liaising with the local law enforcement.

MAIN OUTCOME MEASURES

Outbreak control.

RESULTS

Laboratory confirmation of clenbuterol in clinical specimens implicated it as the heroin adulterant. Thirteen patients met clinical and epidemiologic criteria for exposure to clenbuterol-adulterated heroin. All patients were associated with a localized area within Richmond, and patient interviews elucidated heroin supplier information. VDH collaborated with local law enforcement agents who investigated and arrested the supplier, leading to cessation of the outbreak.

CONCLUSION

This outbreak highlights the value of policies and practices that support an integrated outbreak response among public health practitioners, poison center staff, laboratorians, clinicians, law enforcement agents, community groups, and other agencies. Collaboration enabled implementation of effective control measures-including those outside the purview of the health department-and should be standard practice in future outbreaks involving illicit substances.

Clenbuterol Food Poisoning from Snake Meat Consumption: An Outbreak of 13 Cases

We report a documented outbreak of clenbuterol food poisoning involving 13 patients who consumed snake meat in Shenzhen. They developed headache, palpitation, tachycardia, hypokalaemia and other symptoms within first 3 hours after exposure. They were initially treated with gastric lavage, fluid and potassium replacement and other supportive measures. All of them completely recovered after admission for up to 48 hours. Public health investigation identified clenbuterol compound in four victims' urine and the food source of snake meat they consumed. (Hong Kong j.emerg.med. 2015;22:46-49)

Unsuspected Clenbuterol Toxicity in a Patient Using Intramuscular Testosterone

Clenbuterol is a beta-agonist that has been abused by fitness-oriented individuals for muscle growth and weight loss. We report a case of a 46-year-old man who presented tachycardic, hypokalemic, and hyperglycemic after injecting testosterone obtained from Brazil. He developed refractory hypotension and was started on an esmolol infusion for suspected beta-agonist toxicity. Laboratory analysis showed a detectable clenbuterol serum concentration. Analysis of an unopened ampule contained boldenone undecylenate, clenbuterol, and vitamin E. This case illustrates a novel exposure that caused beta-agonist toxicity and was treated successfully with rapid-onset beta blocker.

Clenbuterol Attenuates hERG Channel by Promoting the Mature Channel Degradation

Clenbuterol, a β2-selective adrenergic receptor agonist, is illicitly used in weight loss and performance enhancement and animal production. Increasing evidence demonstrates that clenbuterol induces various kinds of arrhythmias and QTc interval prolongation. However, little is known about the underlying mechanism. Most drugs are associated with QTc prolongation through interfering with human ether-a-go-go-related gene (hERG) K⁺ channels. The present study aims to investigate the effects and underlying mechanisms of clenbuterol on the hERG channel. HEK 293 cells were transfected with wild type and Y652A or F656A mutants of the hERG channel and treated with clenbuterol. The hERG current was recorded using whole-cell patch-clamp technique, and protein level was evaluated by Western blot. We found that clenbuterol decreases the mature form of the hERG protein at the cell membrane in a concentration- and time-dependent manner, without affecting the immature form. Correspondingly, clenbuterol chronic treatment reduced hERG current to a greater extent compared to acute treatment. In the presence of Brefeldin A (BFA), which was used to block hERG channel trafficking to cell membrane, clenbuterol reduced hERG on plasma membrane to a greater extent than BFA alone. In addition, the hERG channel's drug binding sites mutant Y652A and F656A abolished clenbuterol-mediated hERG reduction and current blockade. In conclusion, clenbuterol reduces hERG channel expression and current by promoting the channel degradation. The effect of clenbuterol on the hERG channel is related to the drug-binding sites, Tyr-652 and Phe-656, located on the S6 domain. This biophysical mechanism may underlie clenbuterol-induced QTc prolongation or arrhythmia.

Hollow Au-Ag Nanoparticles Labeled Immunochromatography Strip for Highly Sensitive Detection of Clenbuterol

The probe materials play a significant role in improving the detection efficiency and sensitivity of lateral-flow immunochromatographic test strip (ICTS). Unlike conventional ICTS assay usually uses single-component, solid gold nanoparticles as labeled probes, in our present study, a bimetallic, hollow Au-Ag nanoparticles (NPs) labeled ICTS was successfully developed for the detection of clenbuterol (CLE). The hollow Au-Ag NPs with different Au/Ag mole ratio and tunable size were synthesized by varying the volume ratio of [HAuCl4]:[Ag NPs] via the galvanic replacement reaction. The surface of hollow Ag-Au NPs was functionalized with 11-mercaptoundecanoic acid (MUA) for further covalently bonded with anti-CLE monoclonal antibody. Overall size of the Au-Ag NPs, size of the holes within individual NPs and also Au/Ag mole ratio have been systematically optimized to amplify both the visual inspection signals and the quantitative data. The sensitivity of optimized hollow Au-Ag NPs probes has been achieved even as low as 2 ppb in a short time (within 15 min), which is superior over the detection performance of conventional test strip using Au NPs. The optimized hollow Au-Ag NPs labeled test strip can be used as an ideal candidate for the rapid screening of CLE in food samples.

Clenbuterol activates the central IL-1 system via the β2-adrenoceptor without provoking inflammatory response related behaviours in rats

The long-acting, highly lipophilic, β2-adrenoceptor agonist clenbuterol may represent a suitable therapeutic agent for the treatment of neuroinflammation as it drives an anti-inflammatory response within the CNS. However, clenbuterol is also known to increase the expression of IL-1β in the brain, a potent neuromodulator that plays a role in provoking sickness related symptoms including anxiety and depression-related behaviours. Here we demonstrate that, compared to the immunological stimulus lipopolysaccharide (LPS, 250μg/kg), clenbuterol (0.5mg/kg) selectively up-regulates expression of the central IL-1 system resulting in a mild stress-like response which is accompanied by a reduction in locomotor activity and food consumption in rats. We provide further evidence that clenbuterol-induced activation of the central IL-1 system occurs in a controlled and selective manner in tandem with its negative regulators IL-1ra and IL-1RII. Furthermore, we demonstrate that peripheral β2-adrenoceptors mediate the suppression of locomotor activity and food consumption induced by clenbuterol and that these effects are not linked to the central induction of IL-1β. Moreover, despite increasing central IL-1β expression, chronic administration of clenbuterol (0.03mg/kg; twice daily for 21days) fails to induce anxiety or depressive-like behaviour in rats in contrast to reports of the ability of exogenously administered IL-1 to induce these symptoms in rodents. Overall, our findings suggest that clenbuterol or other selective β2-adrenoceptor agonists could have the potential to combat neuroinflammatory or neurodegenerative disorders without inducing unwanted symptoms of depression and anxiety.

Case of low dose clenbuterol toxicity

We present a case of acute clenbuterol toxicity following ingestion of 20 μg of clenbuterol, resulting in symptoms of sympathetic activation, sinus tachycardia and electrolyte derangement. The patient was managed conservatively with fluid resuscitation, electrolyte replacement and monitoring, and discharged following a 5-day stay in hospital.

Case of low dose clenbuterol toxicity

We present a case of acute clenbuterol toxicity following ingestion of 20 μg of clenbuterol, resulting in symptoms of sympathetic activation, sinus tachycardia and electrolyte derangement. The patient was managed conservatively with fluid resuscitation, electrolyte replacement and monitoring, and discharged following a 5-day stay in hospital.

Pharmacokinetics of ambroxol and clenbuterol tablets in healthy Chinese volunteers

OBJECTIVE

To investigate the pharmacokinetics of Ambroxol and Clenbuterol Tablets in Chinese healthy volunteers after a single or multiple dosages oral administration.

METHODS

A total of 9 healthy adult subjects were given Ambroxol and Clenbuterol Tablets in a single dosage or multiple dosages respectively. LC/MS/MS were used for the determination of Ambroxol and Clenbuterol of in plasma. The important pharmacokinetic parameters were calculated by DAS 2.0 software (compartment model).

RESULTS

Single and multiple dosage groups of Ambroxol and Clenbuterol were all fitted two-compartment model. The pharmacokinetics fitted first order kinetics process. No difference in pharmacokinetics of Ambroxol in single and multiple dosage groups volunteers was observed, Which showed no marked changes, suggesting that multiple dosing did not influence the velocity of drug metabolism. Moreover, parameters of Clenbuterol had significant difference between the single and multiple dosage groups (P<0.05), showing there was accumulation in the body. 9 subjects had completed single or multiple dosages oral administration test, with no adverse drug reactions appeared during the test.

CONCLUSION

There was no obvious accumulation of Ambroxol after repeated dosing. But obvious accumulation of Clenbuterol was noted in multiple-dose administration. The established method is sensitive, accurate, reliable and specific, and it can meet the requirement of clinical pharmacokinetic trial.

A descriptive study of adverse events from clenbuterol misuse and abuse for weight loss and bodybuilding

BACKGROUND

Clenbuterol is a β2-agonist approved in the United States for veterinary use in nonfood animals. Clenbuterol use is emerging among bodybuilders and fitness enthusiasts attracted to the hypertrophic and lipolytic effects.

CASES

This was a retrospective chart review of clenbuterol exposures reported to 2 poison control centers. Misuse of clenbuterol for weight loss and bodybuilding was reported in 11 of 13 clenbuterol users. Reported clinical effects included tachycardia, widened pulse pressure, tachypnea, hypokalemia, hyperglycemia, ST changes on electrocardiogram (ECG), elevated troponin, elevated creatine phosphokinase (CPK), palpitations, chest pain, and tremor. Measured serum clenbuterol concentration was 2983 pg/mL post 4.5 mg ingestion. Co-ingestants included T3 and anabolic steroids. Treatments included activated charcoal, benzodiazepines, β-blockers, potassium replacement, and intravenous (IV) fluid.

CONCLUSIONS

There is an increasing use of the Internet for illicit drug use for bodybuilding and weight loss purposes. These patients may not present as the stereotype of illicit drug abusers, but as healthy athletic low-risk patients. Clinical effects persisted greater than 24 hours with evidence of myocardial injury in 2 patients. Clenbuterol is increasingly being abused within the bodybuilding subculture. These cases illustrate the hidden dangers of clenbuterol abuse among bodybuilders and fitness enthusiasts.

Clenbuterol toxicity: a NSW poisons information centre experience

OBJECTIVE

To describe the epidemiology and toxicity of clenbuterol in exposures reported to the NSW Poisons Information Centre (NSWPIC).

DESIGN AND SETTING

Retrospective observational study analysing data from all calls about clenbuterol exposure recorded in the NSWPIC database from 1 January 2004 to 31 December 2012. The NSWPIC coversthe Australian jurisdictions New South Wales, Tasmania and the Australian Capital Territory 24 hours a day and provides after-hours cover for the rest of Australia for 7 nights each fortnight.

MAIN OUTCOME MEASURES

Total number of exposures, source of call (hospital, health care worker, member of the public), time from exposure to call, reasons for drug use, clinical features and advice given.

RESULTS

Callers reported 63 exposures to clenbuterol, with a dramatic increase from three in 2008 to 27 in 2012. Of the 63 calls, 35 were from hospital, two from paramedics, one from general practice and 21 direct from the public. At least 53 patients (84%) required hospitalisation. The commonest reasons for use were bodybuilding and slimming. The most common features were tachycardia (24 patients), gastrointestinal disturbance (16) and tremor (11). Exposure was also associated with cardiotoxicity including one cardiac arrest in a 21-year-old man.

CONCLUSION

Although a well recognised doping issue among elite athletes, clenbuterol use has spread out into the general public, especially during 2012, and should be considered in patients using bodybuilding or slimming products who present with protracted sympathomimetic features. The potential for misuse of this substance requires reconsideration of its current poison schedule registration and its availability.

Torsade de pointes associated with the combination of solifenacin and clenbuterol for urinary incontinence

A 79-year-old woman undergoing medical treatment with solifenacin and clenbuterol for urinary incontinence was admitted to our hospital because of recurrent syncope. Her syncope appeared one month after the doses of clenbuterol were increased. Torsade de pointes (TdP) was evident on her Holter electrocardiogram at the time when she developed syncope. Ultimately, a cardioverter-defibrillator with dual chamber pacing capability was implanted. To our knowledge, this is the first report of TdP associated with the combination of solifenacin and clenbuterol for urinary incontinence. <Learning objective: Urinary incontinence increases with age. Muscarinic receptor antagonists are considered the mainstay of pharmacologic treatment for this condition. Some patients might be treated with a combination of a bladder selective muscarinic receptor antagonist solifenacin and a long-acting β2 adrenergic agonist clenbuterol. However, this combination therapy may cause torsade de pointes with syncope.>.

Case report and review of clenbuterol cardiac toxicity

Clenbuterol is an oral β2-agonist utilized as an illicit substance for performance-enhancement or weight loss. We report a case of a 23-year-old male who presented with anxiety and chest tightness after intentional ingestion of 5000 μg of clenbuterol (125 times the recommended adult dose) to lose weight. His electrocardiogram showed sinus tachycardia and diffuse nonspecific repolarization abnormalities with mild inferolateral ST-segment depression. Bloodwork revealed a potassium of 2.0 mmol/L, peak lactate of 9.4 mmol/L, and peak troponin of 5.39 μg/L. A transthoracic echocardiogram was normal except for hyperdynamic left ventricular function. He was treated with intravenous fluids and oral metoprolol. His tachycardia and electrocardiogram abnormalities resolved after 48 h. Clenbuterol has gained notoriety in recent years as a drug of abuse and cases of toxicity will likely continue to increase due to its relative attainability and readily accessible online dosing information. Patients often present with agitation, palpitations, tachycardia, hypokalemia, and hyperglycemia. Treatment is supportive with intravenous fluids, β-blockers, and potassium supplementation. <Learning objective: Clenbuterol, an oral β2-agonist, can be utilized as an illicit substance for performance-enhancement or weight loss. Cardiac toxicity and type II myocardial infarction can occur with clenbuterol overdoses. Associated symptoms include agitation, palpitations, tachycardia, hypokalemia, and hyperglycemia. Treatment is supportive primarily with intravenous fluid, β-blockers, and potassium supplementation.>.

Hair analysis, a reliable and non-invasive method to evaluate the contamination by clenbuterol

The illegal use of clenbuterol has been an increasingly serious issue in today's livestock products industry. It becomes an important project to develop a reliable approach to detect its content in food animals. A simple and sensitive LC-MS/MS method was developed to detect clenbuterol residue in hair, with the low limit of quantitation (LLOQ) about 0.5ng/g. Hogs fed with 340µg/day of clenbuterol for 2 weeks were found a high clenbuterol residue in their hair approximately at 1-2 months after withdrawal. There remained 3.31ng/g clenbuterol in hog hair approximately 5 months after the last administration, focused on the tip of the hair (mainly in hogs with dark hair). An extensive contamination was observed in twenty investigated market hogs whose dark hair obviously had a higher clenbuterol residue than the light ones (p=0.017, t test). Volunteers (60.3 percent) from Xuhui district (Shanghai) were found to have a detectable amount of clenbuterol in their hair (>0.5ng/g). In conclusion, hair residue detection is a reliable method to evaluate the clenbuterol contamination in animals and humans. Meat supply in the Xuhui district might have serious potential safety risks which should be further investigated and discussed to determine the safety range of clenbuterol residue.

Cation interdependency in acute stressor states

Acute stressor states are inextricably linked to neurohormonal activation which includes the adrenergic nervous system. Consequent elevations in circulating epinephrine and norepinephrine unmask an interdependency that exists between K+, Mg2+ and Ca2+. Catecholamines, for example, regulate the large number of Mg2+-dependent Na/K ATPase pumps present in skeletal muscle. A hyperadrenergic state accounts for a sudden translocation of K+ into muscle and rapid appearance of hypokalemia. In the myocardium, catecholamines promote Mg2+ efflux from cardiomyocytes, whereas intracellular Ca2+ influx and overloading account for the induction of oxidative stress and necrosis of these cells with leakage of their contents, including troponins. Accordingly, acute stressor states can be accompanied by nonischemic elevations in serum troponins, together with the concordant appearance of hypokalemia, hypomagnesemia and ionized hypocalcemia, causing a delay in myocardial repolarization and electrocardiographic QTc prolongation raising the propensity for arrhythmias, including atrial fibrillation and polymorphic ventricular tachycardia. In this review, we focus on the interdependency between K+, Mg2+ and Ca2+ which are clinically relevant to acute stressor states.

Persistent wandering atrial pacemaker after epinephrine overdosing - a case report

BACKGROUND

Long-term complications of sympathomimetic drug overdosing have not been adequately investigated in infants and young children. Despite reports discouraging their use in children, these formulations are frequently administered for "cold-like symptoms". Their frequent adverse events are different forms of arrhythmias, including multifocal atrial tachycardia.

CASE PRESENTATION

A 3-year-old toddler developed multifocal atrial tachycardia following an iatrogenic overdose of epinephrine accidentally administered intravenously. His ECG showed wandering atrial pacemaker (p-waves with different origins and configurations) that persisted for at least one year. This event demonstrated the sensitivity of young children to the sympathomimetic drugs, especially overdosing.

CONCLUSIONS

Health care providers and parents should be warned of toxicities associated with sympathomimetic drug overdosing. Future studies are needed to determine whether wandering atrial pacemaker is a potential long-term complication of high-dose sympathomimetics.

Drug-induced atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common arrhythmia and an important cause of hospitalization, morbidity, and mortality. A myriad of drugs can induce AF. However, drug-induced AF (DIAF) receives little attention. Thus, this review is an attempt to attract the attention on this adverse effect.

AREAS COVERED

Published reports of drug-induced AF (DIAF) are reviewed in this paper, from January 1974 to December 2011, using the PubMed/Medline database and lateral references.

EXPERT OPINION

In most cases, DIAF is paroxysmal and terminates spontaneously, but sometimes AF persists and it is necessary to perform a cardioversion to restore sinus rhythm and avoid progression to persistent AF. Because of the short duration of DIAF, in addition to physicians/patients not being knowledgeable about this side effect, the real incidence and clinical consequences of DIAF are presently unknown. DIAF is an increasing problem, as some widely prescribed drugs can present this adverse effect. The risk is expected to increase in the elderly and in patients with comorbidities. It is important that physicians understand the significance of DIAF, to increase the collaboration between cardiac and non-cardiac professionals, and to educate patients to make them aware of this adverse side effect.

Toxicity of weight loss agents

INTRODUCTION

With the rise of the obesity epidemic in the United States over the last several decades and the medical complications seen with it, weight loss and dieting have become a national public health concern.

DISCUSSION

Because of their increased use and availability through internet sales, several different dieting agents were reviewed for potential toxicity. These included: syrup of ipecac, cathartics, human chorionic gonadotropin hormone, 2,4 Dinitrophenol, guar gum, phenylpropanolamine, ma huang/ ephedra, caffeine, clenbuterol, fenfluramine, sibutramine, thyroid hormone, orlistat and cannabinoid antagonists.

CONCLUSIONS

With the internet making even banned products readily accessible, healthcare providers need to be aware of the potential toxicities of a wide range of weight loss agents. Our review covered topics we thought to be most historically significant as well as pertinent to the practice of medical toxicology today.