A Case Series of Clenbuterol Toxicity Caused by Adulterated Heroin

Asthma and COPD: A Focus on β-Agonists - Past, Present and Future

Asthma has been recognised as a respiratory disorder for millennia and the focus of targeted drug development for the last 120 years. Asthma is one of the most common chronic non-communicable diseases worldwide. Chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide, is caused by exposure to tobacco smoke and other noxious particles and exerts a substantial economic and social burden. This chapter reviews the development of the treatments of asthma and COPD particularly focussing on the β-agonists, from the isolation of adrenaline, through the development of generations of short- and long-acting β-agonists. It reviews asthma death epidemics, considers the intrinsic efficacy of clinical compounds, and charts the improvement in selectivity and duration of action that has led to our current medications. Important β2-agonist compounds no longer used are considered, including some with additional properties, and how the different pharmacological properties of current β2-agonists underpin their different places in treatment guidelines. Finally, it concludes with a look forward to future developments that could improve the β-agonists still further, including extending their availability to areas of the world with less readily accessible healthcare.

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.

Opioid overdoses involving xylazine in emergency department patients: a multicenter study

INTRODUCTION

Illicit opioids, consisting largely of fentanyl, novel synthetic opioids, and adulterants, are the primary cause of drug overdose fatality in the United States. Xylazine, an alpha-2 adrenergic agonist and veterinary tranquilizer, is being increasingly detected among decedents following illicit opioid overdose. Clinical outcomes in non-fatal overdose involving xylazine are unexplored. Therefore, among emergency department patients with illicit opioid overdose, we evaluated clinical outcome differences for patients with and without xylazine exposures.

METHODS

This multicenter, prospective cohort study enrolled adult patients with opioid overdose who presented to one of nine United States emergency departments between 21 September 2020, and 17 August 2021. Patients with opioid overdose were screened and included if they tested positive for an illicit opioid (heroin, fentanyl, fentanyl analog, or novel synthetic opioid) or xylazine. Patient serum was analyzed via liquid chromatography quadrupole time-of-flight mass spectroscopy to detect current illicit opioids, novel synthetic opioids, xylazine and adulterants. Overdose severity surrogate outcomes were: (a) cardiac arrest requiring cardiopulmonary resuscitation (primary); and (b) coma within 4 h of arrival (secondary).

RESULTS

Three hundred and twenty-one patients met inclusion criteria: 90 tested positive for xylazine and 231 were negative. The primary outcome occurred in 37 patients, and the secondary outcome occurred in 111 patients. Using multivariable regression analysis, patients positive for xylazine had significantly lower adjusted odds of cardiac arrest (adjusted OR 0.30, 95% CI 0.10-0.92) and coma (adjusted OR 0.52, 95% CI 0.29-0.94).

CONCLUSIONS

In this large multicenter cohort, cardiac arrest and coma in emergency department patients with illicit opioid overdose were significantly less severe in those testing positive for xylazine.

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.

Excretion and Residual Concentration Correlations of Salbutamol Between Edible Tissues and Living Samples in Pigs and Goats

Illegal use of salbutamol (SAL), a β-adrenergic leanness-enhancing agent, has posed potential threat to human health in China. The excretion and depletion of SAL in pigs and goats were investigated, and the concentration correlations between edible tissues and living samples were analyzed to find out a suitable living sample for pre-slaughter monitoring of SAL in pigs and goats. After a single oral dosage of 1.2 mg/kg SAL, approximately 70% of the dose was excreted by pigs and goats from their excreta. When pigs and goats were supplied feed containing SAL (20 mg/kg) for 14 consecutive days, high concentrations of SAL were observed in the liver and kidneys, and the longest persistence was observed in hair. Unlike pigs, SAL was presented primarily as conjugated SAL in goats. Excellent concentration correlations of SAL were observed between urine and edible tissues both in pigs and goats, and in addition, good correlations also were found between hair and edible tissues in pigs and between feces and edible tissues in goats. Hence, urine and hair could accurately predict SAL concentrations in edible tissues of pigs, whereas feces and urine were satisfactory for predicting SAL concentrations in edible tissues of goats. These data make it possible for pre-slaughter monitoring of SAL residues in the edible tissues of pigs and goats.

Extracellular and intracellular zilpaterol and clenbuterol quantification in Hep G2 liver cells by UPLC-PDA and UPLC-MS/MS

Zilpaterol and Clenbuterol are β-adrenergic agonists that have been widely used to feed cattle. Although the use of Zilpaterol has been approved, Clenbuterol is still used illegally at unknown doses. However, the research of both substances has been based mainly on the evaluation of residues. To our knowledge, this is the first time that a cellular model using Hep G2 cells treated with Zilpaterol and Clenbuterol is presented as an alternative approach to quantify both drugs at the cellular level. Thus, a complete analytical methodology has been developed for the accurate quantitation of these β-adrenergic agonists in both cellular compartments. We propose the use of ultra-performance liquid chromatography with photodiode array detector (UPLC-PDA) for extracellular determinations while UPLC coupled to a tandem mass spectrometer (UPLC-MS/MS) for intracellular analysis. The methods were fully validated in terms of selectivity, linearity, accuracy, and precision, limits of detection and quantitation (LOD and LOQ, respectively), stability, carryover, and matrix effect. The method for intracellular content was linear ranging from 0.25 to 8 ng/mL while for extracellular content, the concentration of Zilpaterol and Clenbuterol ranged from 0.125 to 4 μg/mL, with correlation coefficients of R > 0.98 and >0.99, respectively. The combination of the two methodologies in the cellular model showed intracellular concentrations of 0.344 ± 0.06 μg/mL and 2.483 ± 0.36 μg/mL for Zilpaterol and Clenbuterol, respectively. Extracellular concentration was 0.728 ± 0.14 μg/mL and 0.822 ± 0.11 μg/mL for Zilpaterol and Clenbuterol, respectively. This work shows the potential applications of cellular modelling in the study of toxicity for the mentioned drugs.

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.

Consumers' Willingness to Pay for Food with Information on Animal Welfare, Lean Meat Essence Detection, and Traceability

Amid high-profile food scares, health concerns and threats of information imperfection and asymmetry, the Chinese pork industry faces increasing demands from consumers for assurances regarding quality and production methods in both the domestic and export markets. Using a real choice experiment (RCE), 316 consumers in Wuxi, located in China's Jiangsu Province, were randomly surveyed to examine the impact of various factors (e.g., traceability, lean meat essence testing, animal welfare, appearance, and price) on consumers' preference and willingness to pay (WTP) for pork products. A random parameter logit model was estimated, and the results show that having a traceable code is the second important factor after price for consumers, corresponding to a WTP of 4.76 yuan per catty, followed by a bright red appearance, a national stocking density standard of animal welfare, and detected no lean meat essence, corresponding to a WTP of more than 2 yuan per catty. In addition, there is a complementary interrelationship between a traceable code and a bright red appearance, detected no lean meat essence, and a national stocking density standard of animal welfare. The results concerning the latent class model (LCM) indicate that 56.9% of consumers are "quality-focused" consumers who are willing to pay a high price for traceable code, detected no lean meat essence, a national stocking density standard of animal welfare, and bright red appearance attributes. A further 28.1% are "price-sensitive" consumers who pay significant attention to the price, and the price that they pay for each product is meagre. The consumers with "preference combination attributes" attach greater value to interaction attributes, such as a traceable code combined with detected no lean meat essence or a bright red appearance and detected no lean meat essence combined with a national stocking density standard of animal welfare or a bright red appearance, accounting for 15% of consumers. The government should improve the traceability system, increase the intensity of lean meat essence testing, promote the welfare level of pigs, and promote public education and publicity on pork quality and safety attributes. Meanwhile, enterprises can formulate "differentiated" pork products, according to different consumer groups, and appropriately increase prices, according to production costs, in order to meet the requirements for pork quality and safety for consumers.

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.

Chemoenzymatic Synthesis of Synthes as Precursors for Enantiopure Clenbuterol and Other β2 Agonists

Clenbuterol is a β2-agonist used in the veterinary treatment of asthma in several countries. The drug is listed on the World Antidoping Agency’s prohibited list due to its effect on increased protein synthesis in the body. However, racemic clenbuterol has recently been shown to reduce the risk of Parkinson’s disease. In order to reveal which one (or both) of the enantiomers that cause this effect, pure enantiomers need to be separately studied. (R)-1-(4-Amino-3,5-dichlorophenyl)-2-bromoethan-1-ol has been synthesised in 93% enantiomeric excess (ee) by asymmetric reduction of the corresponding ketone catalysed by a ketoreductase and nicotinamide adenine dinucleotide phosphate (NADPH) as the cofactor in dimethyl sulfoxide (DMSO). (S)-N-(2,6-Dichloro-4-(1-hydroxyethyl)phenyl)acetamide has been synthesised in >98% ee by the same system. Both synthons are potential precursors for clenbuterol enantiomers.

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.