A case of fatal caffeine poisoning

Toxicity Potential of Nutraceuticals

During the past few decades and especially during and after the COVID-19 pandemic, the use of nutraceuticals has become increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have an inherent toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies and biomarkers of exposure, effect, and susceptibility appears to play a pivotal role in the safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly or when polypharmacy is involved. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors that influence their safety.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Caffeine Consumption Helps Honey Bees Fight a Bacterial Pathogen

Caffeine has long been used as a stimulant by humans. Although this secondary metabolite is produced by some plants as a mechanism of defense against herbivores, beneficial or detrimental effects of such consumption are usually associated with dose. The Western honey bee, Apis mellifera, can also be exposed to caffeine when foraging at Coffea and Citrus plants, and low doses as are found in the nectar of these plants seem to boost memory learning and ameliorate parasite infection in bees. In this study, we investigated the effects of caffeine consumption on the gut microbiota of honey bees and on susceptibility to bacterial infection. We performed in vivo experiments in which honey bees, deprived of or colonized with their native microbiota, were exposed to nectar-relevant concentrations of caffeine for a week, then challenged with the bacterial pathogen Serratia marcescens. We found that caffeine consumption did not impact the gut microbiota or survival rates of honey bees. Moreover, microbiota-colonized bees exposed to caffeine were more resistant to infection and exhibited increased survival rates compared to microbiota-colonized or microbiota-deprived bees only exposed to the pathogen. Our findings point to an additional benefit of caffeine consumption in honey bee health by protecting against bacterial infections. IMPORTANCE The consumption of caffeine is a remarkable feature of the human diet. Common drinks, such as coffee and tea, contain caffeine as a stimulant. Interestingly, honey bees also seem to like caffeine. They are usually attracted to the low concentrations of caffeine found in nectar and pollen of Coffea plants, and consumption improves learning and memory retention, as well as protects against viruses and fungal parasites. In this study, we expanded these findings by demonstrating that caffeine can improve survival rates of honey bees infected with Serratia marcescens, a bacterial pathogen known to cause sepsis in animals. However, this beneficial effect was only observed when bees were colonized with their native gut microbiota, and caffeine seemed not to directly affect the gut microbiota or survival rates of bees. Our findings suggest a potential synergism between caffeine and gut microbial communities in protection against bacterial pathogens.

Development of a Caffeine Content Table for Foods, Drinks, Medications and Supplements Typically Consumed by the Brazilian Population

Background: The lack of a national table informing the caffeine contents in foods, drinks, dietary supplements, and medications sold in Brazil added to the noncompulsory disclosure of caffeine contents on labels of food products makes it difficult to estimate caffeine consumption in the Brazilian population. Therefore, this study aimed to develop the Brazilian Caffeine Content Table (BraCaffT). Methods: A systematic search for caffeine levels in foods, drinks, recipes, supplements, and medications was performed through a literature review, afterward collecting data from the United States Department of Agriculture Food Data Central, information from manufacturers’ and websites, and the Brazilian official medication guide. Subsequently, data systematization was performed in a spreadsheet with standardized values presented in mg of caffeine per 100 g or 100 mL of food or drink and a capsule or pill for medications and some dietary supplements. Results: The BraCaffT presents 57 items, divided into 11 categories: coffees, teas and infusions, cocoa powder, chocolates, cocoa-based beverages, desserts, soft drinks, energy drinks, guaraná powder, dietary supplements, and medications. Conclusions: The BraCaffT emerges as an instrument of great relevance and wide applicability in clinical contexts, in academic research, and as a database for the Brazilian population to better understand the amounts of caffeine in foods, drinks, dietary supplements, and medications consumed daily favoring a safe intake.

A case of refractory ventricular fibrillation after caffeine poisoning successfully treated by supportive care

Caffeine (1,3,7-trimethylxantine), a structural analog of adenosine, is widely used as a central nervous system stimulant in beverages and drugs. Caffeine overdose induces hypokalemia, fatal ventricular fibrillation, and cardiac arrest, resulting in death. We describe a case of caffeine overdose that presented with refractory ventricular fibrillation that was treated with supportive care because invasive care for severely ill patients was limited due to the COVID-19 pandemic. A 20-year-old woman with no underlying medical history ingested 90,200-mg caffeine tablets (total dose 18 g) in a suicide attempt. She was transported to the emergency department 45 min after ingestion with dizziness, palpitations, nausea, and vomiting. She developed cardiac arrest 80 min after ingesting the caffeine, with refractory ventricular tachycardia that recurred for about 2.5 h. Advanced life support including defibrillation was started immediately and we gave intravenous Intralipid emulsion, potassium chloride, amiodarone, and esmolol, without hemodialysis or extracorporeal membrane oxygenation (ECMO). The ventricular fibrillation was stopped 4 h after ingestion. As supportive care, mechanical ventilation, sedatives, and neuromuscular blockade were continued until 12 h after ingestion. Although she suffered from prolonged, refractory ventricular tachycardia, she recovered without complications. This case report describes the clinical course of severe caffeine intoxication without an active elimination method, such as hemodialysis or ECMO and explores the treatment of caffeine intoxication with a literature review.

Classification of the mechanisms by which cardiotoxic plant poisons exert their effects

Episodes of poisoning due to plant-based toxins are an unusual presentation to the emergency department. Plant poisons may be ingested if the source plant is misidentified as benign (eg, Lily of the Valley being mistaken for wild garlic and water hemlock being mistaken for wild celery), or taken as part of a complementary medicine regime or otherwise for psychotropic effect. Numerous plant poisons demonstrate cardiotoxic effects resulting from action against cardiac myocyte ion channels, or other cardiac receptor targets. These mechanisms will produce stereotyped symptoms and including electrocardiogram (ECG) changes dependent on which ion channels or receptors are targeted. These mechanisms are stereotyped and may be grouped by toxidromic effect. This article proposes a novel classification of cardiotoxic plant poisons based on these actions. Given that these mechanisms mirror the Vaughan Williams classification used to categorise therapeutic antiarrhythmic agents, it is felt that this will serve as a mnemonic and diagnostic aid in clinical situations of cardiotoxic plant ingestion.

Energy Drinks and Sports Performance, Cardiovascular Risk, and Genetic Associations; Future Prospects

The consumption of energy drinks (e.g., containing caffeine and taurine) has increased over the last decade among adolescents and athletes to enhance their cognitive level and improve intellectual and athletic performance. Numerous studies have shown that drinking moderate doses of such drinks produces beneficial effects, as they considerably boost the sporting performance of elite athletes in various sports, including both endurance and explosive events. However, apart from their ergogenic effects, the regular consumption of energy drinks also increases blood pressure and consequently incites problems such as hypertension, tachycardia, and nervousness, all of which can lead to cardiovascular disorders. A potential positive correlation between genetics and the moderate consumption of energy drinks and athletic performance has recently been reported; notwithstanding, a better understanding of the genetic variants involved in metabolism is a key area for future research to optimize the dose of energy drink consumed and obtain the maximal ergogenic effect in elite sports. The aim of this literature review, therefore, is to present the results of recent studies, classifying them according to the differences in the associations between energy drinks and: (i) Athletic performance; (ii) cardiovascular risk factors while practicing sports; and (iii) genetic associations and future prospects between the consumption of energy drinks and performance.

LC-MS/MS method for rapid and accurate detection of caffeine in a suspected overdose case

Excessive intake of caffeine, otherwise known to be a safe and mild central nervous system stimulant, causes nausea, vomiting, convulsions, tachycardia, and eventually fatal arrhythmias and death. Caffeine intoxication, a global problem, has been increasing in Japan since 2013. Thus, there is a need for rapid and accurate diagnosis of caffeine poisoning in forensic and clinical toxicology investigations. Herein, we demonstrate rapid and accurate caffeine quantitation by liquid chromatography tandem mass spectrometry using the standard addition method in a fatal case. Biological samples were diluted 500-100,000-fold and subjected to a simple pretreatment (adding caffeine standard and internal standard and passing through a lipid removal cartridge). The multiple reaction monitoring transitions were 195 → 138 for quantitation, 195 → 110 for the qualifier ion, and 204 → 144 for the internal standard (caffeine-d9). The standard plots were linear over 0-900 ng/mL (r² = 0.9994-0.9999) for biological samples, and the reproducibility (%RSD) of the method was 1.53-6.97% (intraday) and 1.59-10.4% (interday). Fatal levels of caffeine (332 μg/mL) and toxic to fatal levels of olanzapine (625 ng/mL), along with other pharmaceuticals were detected in the external iliac venous blood. The cause of death was determined to be multi-drug poisoning, predominantly caused by caffeine. Our method is useful for not only forensic cases but also the rapid diagnosis of caffeine overdose in emergency clinical settings.

Massive β1-Adrenergic Receptor Reaction Explains Irreversible Acute Arrhythmia in a Fatal Case of Acute Pure Caffeine Intoxication

Caffeine, a naturally occurring purine-based alkaloid, is the most consumed psychostimulant worldwide. Since caffeine pharmacokinetics shows extreme interindividual variability, it is not easy to establish its toxic dose. Only a few cases of death due to acute caffeine intoxication have been described so far, the majority of which attributable to massive assumption of caffeine-based medications. We present a case of acute caffeine overdose due to ingestion of pure caffeine. The extremely high blood concentration of caffeine determined a strong cardiovascular response, leading to fatal arrhythmia, as supported by histological evidence of myocardial injury. Quantitation of catecholamines and their metabolites in urine samples was performed and showed level near the highest limit of normal ranges for norepinephrine and high level of epinephrine. Contraction band is a pathological modification of the myocell caused by the catecholaminergic action and can occur in conditions of alteration due to the interaction between calcium and catecholamines. We demonstrated the β1-adrenoceptor involvement in our fatal case by immunohistochemical analysis.

The adulterated XANAX pill: a fatal intoxication with etizolam and caffeine

A 49-year old man was found dead at home next to a glass containing a dried, white, crystalline substance and near a bag containing pills with the imprint XANAX, the trade name of alprazolam. A comprehensive screening of material collected during the autopsy revealed the presence of etizolam and caffeine in lethal concentrations (0.77 μg/mL and 190 μg/mL) but no trace of alprazolam. Benzodiazepine analogue etizolam is rarely prescribed in Germany, and as a result there are not many reports about fatal cases. It has anxiolytic, hypnotic, sedative and muscle-relaxant properties and is used for the short-term treatment of anxiety and panic attacks. The purine alkaloid caffeine, conversely, is the most widely used central nervous system stimulant. The following report outlines potentially the first reported case of a lethal combination of the downer etizolam and the upper caffeine in medical literature.

Urinary glucose and ketone bodies as indicators of acute caffeine poisoning

AIM

In various countries, many fatal health problems have been reported due to high intake of caffeine-rich energy drinks, tablets, and powders. In patients with acute caffeine poisoning, determination of blood caffeine concentration is an important yet difficult task. We aimed to assess whether the presence of glucose and ketone bodies in urine reflected the blood caffeine concentration in patients with acute caffeine poisoning.

METHODS

From April 2010 to March 2018, 25 patients with an overdose of only caffeine-rich tablets were admitted to our hospital. Their clinical features were investigated. In addition, we investigated whether the glucose and ketone bodies in the urine reflected blood caffeine concentration in 23 patients who underwent the urine qualitative test at admission.

RESULTS

The majority of the patients were young healthy women, whose average caffeine ingestion was 15.6 ± 8.1 g. Initial urine examinations showed glucose in 60% (14/23) of patients and ketone bodies in 57% (13/23) of patients. Ketone bodies or glucose were found in 78% (18/23) of the patients. The correlation between blood caffeine concentration and urinary glucose was R = 0.625, blood caffeine concentration and ketone bodies was R = 0.596, and blood caffeine and both was R = 0.76.

CONCLUSION

Urine qualitative test is effective for differential diagnosis and severity assessment of acute caffeine poisoning in patients.

Extracorporeal Membrane Oxygenation for Hypokalemia and Refractory Ventricular Fibrillation Associated with Caffeine Intoxication

BACKGROUND

Caffeine has been reported as a cause of cardiac arrest after massive overdose. Here, we report the case of a patient with caffeine intoxication, which can cause fatal dysrhythmias and severe hypokalemia. They were successfully treated with extracorporeal membrane oxygenation (ECMO).

CASE REPORT

A 43-year-old woman with a history of bipolar disorder presented to the emergency department after suicidal drug ingestion (caffeine and amitriptyline). Immediately after arrival, she experienced multiple episodes of ventricular fibrillation with severe hypokalemia requiring cardiopulmonary resuscitation and medical therapy. However, conventional treatment was not successful. We instituted ECMO early during resuscitation because prolonged hypokalemia refractory to aggressive potassium replacement precluded the use of antidysrhythmic medications for refractory circulatory compromise with ventricular fibrillation. The use of ECMO provided time to correct hypokalemia (19.3 g potassium) and reduce the caffeine level with hemodialysis. Although she had sustained cardiac arrest, she recovered fully and was discharged home. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case indicates the potential effectiveness of ECMO in severely poisoned patients with fatal dysrhythmias. ECMO could provide time for removal of toxic drugs and correction of electrolyte abnormalities.

European Cardiac Arrhythmia Society Statement on the cardiovascular events associated with the use or abuse of energy drinks

Energy drinks are increasingly used by young people and young athletes in order to improve their performance alone or in association of other substances, particularly alcohol. In recent years, a number of reports of reports have raised attention on the side-effects associated with the use or abuse of energy drinks particularly serious cardiovascular events. The European Cardiac Arrhythmia Society (ECAS) has undertaken a systematic and critical review of reported data on cardiovascular events including life-threatening arrhythmias with or without cardiac arrest and other cardiovascular events, and discussed in this review the possible causal effect of caffeine and other ingredients contained in energy drinks and the reported events. Twenty-two cardiovascular events were reported in association with the use or abuse of energy drinks. The European Cardiac Arrhythmia Society would like to draw attention on the possible cardiovascular complications that may occur with the consumption of these beverages and to emphasize the prevention measures to be taken particularly in the young population. Well-designed prospective studies are needed to clarify the possible role of energy drinks in inducing the cardiovascular events reported.

Energy Drinks Induce Acute Cardiovascular and Metabolic Changes Pointing to Potential Risks for Young Adults: A Randomized Controlled Trial

BACKGROUND

Case reports suggest a link between energy drinks (EDs) and adverse events, including deaths.

OBJECTIVES

We examined cardiovascular and metabolic effects of EDs and mixtures providing relevant ingredients of EDs compared to a similarly composed control product (CP) without these components.

METHODS

This randomized, crossover trial comprised 38 adults (19 women, mean BMI 23 kg/m2, mean age 22 y). We examined effects of a single administration of a commercial ED, the CP, and the CP supplemented with major ED-ingredients at the same concentrations as in the ED. The study products were administered at 2 volumes, 750 or 1000 mL.

RESULTS

Both volumes of the study products were acceptably tolerated with no dose-dependent effects on blood pressure (BP, primary outcome), heart rate, heart rate corrected duration of QT-segment in electrocardiography (QTc interval), and glucose metabolism. After ED consumption, 11% of the participants reported symptoms, in contrast to 0-3% caused by other study products. After 1 h, administration of an ED caused an increase in systolic BP (116.9 ± 10.4 to 120.7 ± 10.7 mmHg, mean ± SD, P < 0.01) and a QTc prolongation (393.3 ± 20.6 to 400.8 ± 24.1 ms, P < 0.01). Also caffeine, but not taurine or glucuronolactone, caused an increase in BP, but no QTc prolongation. The BP effects were most pronounced after 1 h and returned to normal after a few hours. All study products caused a decrease in serum glucose and an increase in insulin concentrations after 1 h compared to baseline values, corresponding to an elevation in the HOMA-IR (ED + 4.0, other products + 1.0-2.8, all P < 0.001).

CONCLUSION

A single high-volume intake of ED caused adverse changes in BP, QTc, and insulin sensitivity in young, healthy individuals. These effects of EDs cannot be easily attributed to the single components caffeine, taurine, or glucuronolactone. This trial was registered at clinicaltrials.gov as NCT01421979.

The clinical toxicology of caffeine: A review and case study

Caffeine is a widely recognized psychostimulant compound with a long history of consumption by humans. While it has received a significant amount of attention there is still much to be learned with respect to its toxicology in humans, especially in cases of overdose. A review of the history of consumption and the clinical toxicology of caffeine including clinical features, pharmacokinetics, toxicokinetics, a thorough examination of mechanism of action and management/treatment strategies are undertaken. While higher (i.e., several grams) quantities of caffeine are known to cause toxicity and potentially lethality, cases of mainly younger individuals who have experienced severe side effects and death despite consuming doses not otherwise known to cause such harm is troubling and deserves further study. An attempted case reconstruction is performed in an effort to shed light on this issue with a focus on the pharmacokinetics and pharmacodynamics of caffeine.

Key Findings and Implications of a Recent Systematic Review of the Potential Adverse Effects of Caffeine Consumption in Healthy Adults, Pregnant Women, Adolescents, and Children

In 2016⁻2017, we conducted and published a systematic review on caffeine safety that set out to determine whether conclusions that were presented in the heavily cited Health Canada assessment, remain supported by more recent data. To that end, we reviewed data from 380 studies published between June 2001 and June 2015, which were identified from an initial batch of over 5000 articles through a stringent search and evaluation process. In the current paper, we use plain language to summarize our process and findings, with the intent of sharing additional context for broader reach to the general public. We addressed whether caffeine doses previously determined not to be associated with adverse effects by Health Canada (400 mg/day for healthy adults, 300 mg/day for pregnant women, 2.5 mg/kg body weight/day for adolescents and children, and 10 g/day for acute effects) remain appropriate for five outcome areas (acute toxicity, cardiovascular toxicity, bone & calcium effects, behavior, and development and reproduction) in healthy adults, pregnant women, adolescents, and children. We used a weight-of-evidence approach to draw conclusions for each of the five outcomes, as well as more specific endpoints within those outcomes, which considered study quality, consistency, level of adversity, and magnitude of response. In general, updated evidence confirms the levels of intake that were put forth by Health Canada in 2003 as not being associated with any adverse health effects, and our results support a shift in caffeine research from healthy to sensitive populations.

Clinical use of plasma lactate concentration. Part 1: Physiology, pathophysiology, and measurement

OBJECTIVE

To review the current literature with respect to the physiology, pathophysiology, and measurement of lactate.

DATA SOURCES

Data were sourced from veterinary and human clinical trials, retrospective studies, experimental studies, and review articles. Articles were retrieved without date restrictions and were sourced primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Lactate is an important energy storage molecule, the production of which preserves cellular energy production and mitigates the acidosis from ATP hydrolysis. Although the most common cause of hyperlactatemia is inadequate tissue oxygen delivery, hyperlactatemia can, and does occur in the face of apparently adequate oxygen supply. At a cellular level, the pathogenesis of hyperlactatemia varies widely depending on the underlying cause. Microcirculatory dysfunction, mitochondrial dysfunction, and epinephrine-mediated stimulation of Na⁺ -K⁺ -ATPase pumps are likely important contributors to hyperlactatemia in critically ill patients. Ultimately, hyperlactatemia is a marker of altered cellular bioenergetics.

CONCLUSION

The etiology of hyperlactatemia is complex and multifactorial. Understanding the relevant pathophysiology is helpful when characterizing hyperlactatemia in clinical patients.

A Retrospective Study on the Epidemiological and Clinical Features of Emergency Patients with Large or Massive Consumption of Caffeinated Supplements or Energy Drinks in Japan

Objective We conducted a retrospective study on the epidemiological and clinical features of patients with acute caffeine poisoning in Japan. Methods Letters requesting participation were sent to 264 emergency departments of hospitals, and questionnaires were mailed to those that agreed to participate. Patients Participants were patients transported to emergency departments of hospitals between April 2011 and March 2016 after consuming large or massive amounts of caffeinated supplements and/or energy drinks (caffeine dose ≥1.0 g). Results We surveyed 101 patients from 38 emergency departments. Since April 2013, the number of patients has markedly increased. Of these young patients (median age, 25 years), 53 were men, and 97 had consumed caffeine in tablet form. Estimated caffeine doses (n=93) ranged from 1.2 to 82.6 g (median, 7.2 g). Serum caffeine levels on admission (n=17) ranged from 2.0 to 530.0 μg/mL (median level, 106.0 μg/mL). Common abnormal vital signs and laboratory data on admission included tachypnea, tachycardia, depressed consciousness, hypercreatinekinasemia, hyperglycemia, hypokalemia, hypophosphatemia, and hyperlactatemia. Common signs and symptoms in the clinical course included nausea, vomiting, excitement/agitation, and sinus tachycardia. Seven patients (6.9%) who had consumed ≥6.0 g of caffeine, or whose serum caffeine levels on admission were ≥200 μg/mL, developed cardiac arrest. Ninety-seven patients (96.0%) recovered completely, but 3 patients (3.0%) died. Conclusion The present analysis of data from more than 100 emergency patients revealed clinical features of moderate to fatal caffeine poisoning. We recommend highlighting the toxicity risks associated with ingesting highly caffeinated tablets.

Dangerous mistake: an accidental caffeine overdose

Caffeine (1,3,7-trimethylxanthine) is a natural product commonly presented in food’s composition, beverages and medicinal products. Generally, it is thought to be safe under normal dosage, yet it can be fatal in case of severe intoxication. We report a case of a healthy 32-year-old woman who went to the local emergency department (ED) 30 min after ingesting, accidentally, 5000 mg of anhydrous caffeine for a preworkout supplement. At the ED, she presented an episode of presyncope followed by agitation. ECG showed polymorphic broad complex QRS tachycardia and arterial blood gas revealed metabolic acidaemia with severe hypokalemia. The dysrhythmia was successfully treated with intravenous propranolol. Acid–base and hydroelectrolytic disorders were also corrected. A persistent sinus tachycardia was observed in the first 2 days in the ward and 5 days later she was discharged asymptomatic with internal medicine follow-up.

Caffeine-Related Deaths: Manner of Deaths and Categories at Risk

Caffeine is the most widely consumed psychoactive compound worldwide. It is mostly found in coffee, tea, energizing drinks and in some drugs. However, it has become really easy to obtain pure caffeine (powder or tablets) on the Internet markets. Mechanisms of action are dose-dependent. Serious toxicities such as seizure and cardiac arrhythmias, seen with caffeine plasma concentrations of 15 mg/L or higher, have caused poisoning or, rarely, death; otherwise concentrations of 3–6 mg/kg are considered safe. Caffeine concentrations of 80–100 mg/L are considered lethal. The aim of this systematic review, performed following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement for the identification and selection of studies, is to review fatal cases in which caffeine has been recognized as the only cause of death in order to identify potential categories at risk. A total of 92 cases have been identified. These events happened more frequently in infants, psychiatric patients, and athletes. Although caffeine intoxication is relatively uncommon, raising awareness about its lethal consequences could be useful for both clinicians and pathologists to identify possible unrecognized cases and prevent related severe health conditions and deaths.

Toxicity Potential of Nutraceuticals

By the turn of the twenty-first century, the use of nutraceuticals became increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have a toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies appears to play a pivotal role in safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors influencing their safety.

Review of Caffeine-Related Fatalities along with Postmortem Blood Concentrations in 51 Poisoning Deaths

Publications reporting concentrations of caffeine in postmortem blood were reviewed if the cause of death was attributed to overdosing (poisoning) with drugs. Age and gender of the deceased, the manner of death (accident, suicide or undetermined) and types of co-ingested drugs were evaluated in relation to the concentrations of caffeine in blood (N = 51). The mean age (±SD) of the victims was 39 ± 17.8 years (range 18-84 years) and most were female (N = 31 or 61%). The difference in mean age of males (42 ± 17.2 years) and females (37 ± 18.3 years) was not statistically significant (t = 0.811, P = 0.421). The mean (±SD), median and range of caffeine concentrations in postmortem blood were 187 ± 96 mg/L (180 mg/L) and 33-567 mg/L, respectively. The median concentration of caffeine in males (161 mg/L) was not significantly different from that of females (182 mg/L), z = 1.18, P = 0.235. There was no correlation between the age of the deceased and the concentration of caffeine in postmortem blood (R2 = 0.026, P > 0.05). Manner of death was classified as suicide in 51% of cases (median blood-caffeine 185 mg/L), accidental in 16% (median 183 mg/L) or undetermined in 33% (median 113 mg/L). The median concentration of caffeine in blood was lower when manner of death was undetermined compared with suicide or accidental (P = 0.023). Although other drugs, including ethanol, antidepressants, antipsychotics, benzodiazepines and/or ephedrine, were often identified in postmortem blood, the predominant psychoactive substance was caffeine. The deceased had ingested caffeine in tablet or powder form and it does not seem likely that toxic concentrations of caffeine can be achieved from over-consumption of caffeinated beverages alone.

Nonfatal and fatal intoxications with pure caffeine - report of three different cases

Caffeine is not usually perceived as a drug by most people because it is found in many foods and drinks, including caffeinated energy drinks, as well as in over the counter analgesics and cold preparations. Recently in Poland it has become increasingly common to take pure caffeine, bought through online stores, as a psychoanaleptic. This creates a much higher risk of severe and even fatal poisoning in comparison with the risk associated with the abuse of food products and non-prescription medicines containing low doses of caffeine. This paper presents three different cases of poisoning that occurred when pure caffeine was taken as psychostimulant; in cases 1 and 2 poisoning was the result of a single overdose, while in the case 3 poisoning resulted from a cumulative overdose. In the case 1 there was a severe intoxication (persistent vomiting, hypotension, tremor), and the concentration of caffeine in the blood was found to be 80.16 μg/mL. The patient was treated using hemodialysis, which caused a rapid decrease in blood levels of caffeine and relief of the clinical symptoms of poisoning. Cases 2 and 3 were fatal poisonings, and recorded levels of caffeine in post mortem blood samples were 140.64 μg/mL and 613.0 μg/mL. In case 2 the patient died 10 min after admission to hospital as a result of sudden cardiac arrest, which was preceded by an attack of convulsions, and in case 3 death occurred in home and was also sudden in nature. Taking pure caffeine as a stimulant is associated with a high risk of overdose and the development of serious and even fatal poisoning, and those using pure caffeine are generally completely unaware of these risks. In such cases, death is usually sudden due to functional mechanisms.

Caffeine: cognitive and physical performance enhancer or psychoactive drug?

Caffeine use is increasing worldwide. The underlying motivations are mainly concentration and memory enhancement and physical performance improvement. Coffee and caffeine-containing products affect the cardiovascular system, with their positive inotropic and chronotropic effects, and the central nervous system, with their locomotor activity stimulation and anxiogenic-like effects. Thus, it is of interest to examine whether these effects could be detrimental for health. Furthermore, caffeine abuse and dependence are becoming more and more common and can lead to caffeine intoxication, which puts individuals at risk for premature and unnatural death. The present review summarizes the main findings concerning caffeine’s mechanisms of action (focusing on adenosine antagonism, intracellular calcium mobilization, and phosphodiesterases inhibition), use, abuse, dependence, intoxication, and lethal effects. It also suggests that the concepts of toxic and lethal doses are relative, since doses below the toxic and/or lethal range may play a causal role in intoxication or death. This could be due to caffeine’s interaction with other substances or to the individuals' preexisting metabolism alterations or diseases.

Legitimacy of concerns about caffeine and energy drink consumption

Whether caffeine and energy drink consumption presents a critical emerging health problem is not currently known. Available evidence suggests that energy drink consumption represents a change in the ways in which individuals in the United States consume caffeine but that the amount of caffeine consumed daily has not appreciably increased. In the present review, the question of whether Americans are sleep deprived (a potential reason for using caffeine) is briefly explored. Reported rates of daily caffeine consumption (based on beverage formulation) and data obtained from both civilian and military populations in the United States are examined, the efficacy of ingredients other than caffeine in energy drinks is discussed, and the safety and side effects of caffeine are addressed, including whether evidence supports the contention that excessive caffeine/energy drink consumption induces risky behavior. The available evidence suggests that the main legitimate concern regarding caffeine and energy drink use is the potential negative impact on sleep but that, otherwise, there is no cause for concern regarding caffeine use in the general population.

Autopsy report for a caffeine intoxication case and review of the current literature

Caffeine (1,3,7-trimethylxanthine) is a popular mild central nervous system stimulant found in the leaves, seeds and fruits of various plants and in foodstuffs such as coffee, tea, and chocolate, among others. Caffeine is widely used and is not associated with severe side effects when consumed at relatively low doses. Although rarely observed, overdoses can occur. However, only a few fatal caffeine intoxication cases have been reported in the literature. Herein, we report the pathological examination results and information on caffeine concentrations in the blood, urine and main organs in a fatal caffeine intoxication case. Even though high caffeine concentrations were found in the systemic organs, no caffeine-related pathological changes were detected.

Cardiac arrest: a case-based review

BACKGROUND

Coffee is commonly consumed among young people in China. However, consumers are rarely aware of physically adverse effects as a result of excessive consumption of caffeine.

DATA SOURCES

A literature search using multiple databases was performed for articles published with concentration on meta-analyses, systematic reviews, and randomized controlled trials.

RESULTS

Excess coffee consumption is also a risk of primary cardiac arrest especially in young people. Treatment modalities include activated charcoals, beta-blockers, vasopressin and hemodialysis when necessary.

CONCLUSION

Coffee consumers should be advised not to routinely take more than moderate coffee.

Fatal caffeine overdose: a case report and review of literature

Caffeine is a central nervous system stimulant that is consumed by large numbers of people on a routine basis, usually in the form of coffee or tea. However, if consumed in high doses, this xanthine alkaloid is profoundly toxic and can result in death. Increasingly being sold as a dietary supplement, many people, particularly those in the health and fitness community, where it is touted as a fitness and muscle building aid, are consuming caffeine anhydrous on a daily basis. We report a case of fatal caffeine overdose in a 39-year-old man resulting from the self-administered ingestion of approximately 12 g of pure caffeine anhydrous. Autopsy blood caffeine levels were 350 mg/L. We recommend mandated labeling of pure caffeine anhydrous, highlighting the toxicity risk of ingesting this chemical; and we recommend ensuring that caffeine levels are included in the comprehensive forensic toxicology panel performed on all cases.

A case of suicide by ingestion of caffeine

Intentional or unintentional caffeine abuse due to excessive intake of beverages or energy drinks containing caffeine is relatively frequent. However, death due to caffeine intoxication is rare and case reports of fatalities from caffeine toxicity are relatively infrequent. In this report, we describe an autopsy case involving a 31 year-old man who intentionally took a large amount of caffeine tablets in the form of a weight loss supplement as part of a suicide plan. Caffeine femoral blood concentration (170 mg/l) was within the toxic and potentially lethal ranges reported in the literature in similar cases. Postmortem biochemistry results suggested depressed glomerular filtration rate and pre-renal failure at the time of death but failed to reveal myoglobinuria, glycosuria, ketonuria or ketonemia. Based on the absence of pathological findings at autopsy and the high blood caffeine level, death was attributed to acute caffeine toxicity. The case emphasizes the usefulness of performing exhaustive toxicology and searching for all potentially relevant information in order to formulate appropriate hypotheses concerning the cause and manner of death.

Plasma lactate concentration as an indicator of plasma caffeine concentration in acute caffeine poisoning

Aim

Severe caffeine poisoning is rare, but is associated with high mortality. Plasma caffeine concentration is one of the indications of treatment of caffeine poisoning; however, it is not easily measured at most emergency departments. If the plasma lactate concentration and the plasma caffeine concentration were correlated, the plasma lactate concentration may be an indication of caffeine poisoning. In this study, we investigated the correlation between the plasma lactate concentration and the plasma caffeine concentration.

Methods

From April 2010 to March 2012, 18 patients with severe caffeine poisoning by overdose were admitted at our Emergency Center. The plasma lactate concentration and plasma caffeine concentration of 10 patients were determined at the same time at 12-24 h after admission. These findings were plotted and we analyzed the correlation and trends in these concentrations.

Results

There were strong correlations between the plasma lactate concentration and the plasma caffeine concentration at admission (n = 18) and at 12-24 h after admission (n = 10) (correlation coefficients, 0.95 and 0.91, respectively). There was a strong positive correlation between the trend of the plasma lactate concentration and the plasma caffeine concentration (n = 10). The correlation coefficient was 0.91.

Conclusion

These results are extremely beneficial for emergency department clinical physicians because such findings permit the determination of the severe caffeine poisoning patient. Additionally, the plasma lactate concentration might be one of the indicators of hospitalization and discharge.

Rhabdomyolysis induced by excessive coffee drinking

Excessive ingestion of caffeine-containing beverages is a rare cause of rhabdomyolysis. Here, we describe the case of a 44-year-old woman presented with nausea, vomiting, palpitations, and tea-colored urine 6 h after drinking a liter of black coffee containing approximately 565 mg of caffeine for mental alertness. Laboratory studies were notable for myoglobinuria and markedly elevated plasma creatine kinase (CK) level of 7315 U/L. With volume expansion and alkalization, her plasma CK level returned to normal within 5 days. Rhabdomyolysis should be considered a potential health hazard from excessive consumption of caffeine-containing products.

Caffeine in floral nectar enhances a pollinator's memory of reward

Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees' bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

Survival of a highly toxic dose of caffeine

A 27-year-old woman with a history of depression and previous overdose presented within 60 min of ingestion of 50 g of caffeine powder. Initially alert but hypotensive and tachycardic, the patient developed a broad complex tachycardia followed by a seizure and multiple ventricular fibrillation (VF) arrests. Following multiple defibrillations for VF, eight cycles of cardiopulmonary resuscitation and treatment with amiodarone, lidocaine, magnesium and potassium supplementation, the patient went to the intensive care unit (ICU). While there, the patient had further VF and required haemofiltration for a profound metabolic acidaemia with cardiac rhythm instability. She developed a postcardiac arrest systemic inflammatory response syndrome with episodes of acute pulmonary oedema, profound vasoplegia, hypothermia and coagulopathy. After 5 days in the ICU, the patient was stable enough to be transferred to the ward, with a persistent sinus tachycardia, and was discharged 3 days later with cardiology and psychiatry follow-up.

Potential toxicity of caffeine when used as a dietary supplement for weight loss

BACKGROUND

Caffeine is added to dietary supplements to increase energy and suppress appetite. Many people take dietary supplements for weight loss. Patients may be unaware that supplements can contain caffeine, even if caffeine is not listed as an ingredient. Commonly used herbal dietary supplement ingredients, such as guarana, are natural sources of caffeine.

OBJECTIVE

To describe a case of possible caffeine-induced seizure in a patient taking an over-the-counter weight loss supplement.

CASE REPORT

A previously healthy 38-year-old female experienced blurring of vision and a new onset grand mal seizure. The patient had a two-month history of taking the dietary supplement, Zantrex - 3™. Zantrex - 3™ is advertised as a weight loss supplement which may provide rapid weight loss and extreme energy in one "power packed pill."

CONCLUSIONS/SUMMARY

After discontinuation of Zantrex - 3™, the patient experienced no further seizure activity. Outpatient follow up at 2 and 6 weeks was noncontributory with follow up MRI and EEG both within normal limits.

International Society of Sports Nutrition position stand: energy drinks

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the safety and efficacy of the use of energy drinks (ED) or energy shots (ES). The ISSN has concluded the following. 1. Although ED and ES contain a number of nutrients that are purported to affect mental and/or physical performance, the primary ergogenic nutrients in most ED and ES appear to be carbohydrate and/or caffeine. 2. The ergogenic value of caffeine on mental and physical performance has been well-established but the potential additive benefits of other nutrients contained in ED and ES remains to be determined. 3. Consuming ED 10-60 minutes before exercise can improve mental focus, alertness, anaerobic performance, and/or endurance performance. 4. Many ED and ES contain numerous ingredients; these products in particular merit further study to demonstrate their safety and potential effects on physical and mental performance. 5. There is some limited evidence that consumption of low-calorie ED during training and/or weight loss trials may provide ergogenic benefit and/or promote a small amount of additional fat loss. However, ingestion of higher calorie ED may promote weight gain if the energy intake from consumption of ED is not carefully considered as part of the total daily energy intake. 6. Athletes should consider the impact of ingesting high glycemic load carbohydrates on metabolic health, blood glucose and insulin levels, as well as the effects of caffeine and other stimulants on motor skill performance. 7. Children and adolescents should only consider use of ED or ES with parental approval after consideration of the amount of carbohydrate, caffeine, and other nutrients contained in the ED or ES and a thorough understanding of the potential side effects. 8. Indiscriminant use of ED or ES, especially if more than one serving per day is consumed, may lead to adverse events and harmful side effects. 9. Diabetics and individuals with pre-existing cardiovascular, metabolic, hepatorenal, and neurologic disease who are taking medications that may be affected by high glycemic load foods, caffeine, and/or other stimulants should avoid use of ED and/or ES unless approved by their physician.

Paradoxical and bidirectional drug effects

A paradoxical drug reaction constitutes an outcome that is opposite from the outcome that would be expected from the drug's known actions. There are three types: 1. A paradoxical response in a condition for which the drug is being explicitly prescribed. 2. Paradoxical precipitation of a condition for which the drug is indicated, when the drug is being used for an alternative indication. 3. Effects that are paradoxical in relation to an aspect of the pharmacology of the drug but unrelated to the usual indication. In bidirectional drug reactions, a drug may produce opposite effects, either in the same or different individuals, the effects usually being different from the expected beneficial effect. Paradoxical and bidirectional drug effects can sometimes be harnessed for benefit; some may be adverse. Such reactions arise in a wide variety of drug classes. Some are common; others are reported in single case reports. Paradoxical effects are often adverse, since they are opposite the direction of the expected effect. They may complicate the assessment of adverse drug reactions, pharmacovigilance, and clinical management. Bidirectional effects may be clinically useful or adverse. From a clinical toxicological perspective, altered pharmacokinetics or pharmacodynamics in overdose may exacerbate paradoxical and bidirectional effects. Certain antidotes have paradoxical attributes, complicating management. Apparent clinical paradoxical or bidirectional effects and reactions ensue when conflicts arise at different levels in self-regulating biological systems, as complexity increases from subcellular components, such as receptors, to cells, tissues, organs, and the whole individual. These may be incompletely understood. Mechanisms of such effects include different actions at the same receptor, owing to changes with time and downstream effects; stereochemical effects; multiple receptor targets with or without associated temporal effects; antibody-mediated reactions; three-dimensional architectural constraints; pharmacokinetic competing compartment effects; disruption and non-linear effects in oscillating systems, systemic overcompensation, and other higher-level feedback mechanisms and feedback response loops at multiple levels. Here we review and provide a compendium of multiple class effects and individual reactions, relevant mechanisms, and specific clinical toxicological considerations of antibiotics, immune modulators, antineoplastic drugs, and cardiovascular, CNS, dermal, endocrine, musculoskeletal, gastrointestinal, haematological, respiratory, and psychotropic agents.

Haemodialysis in massive caffeine intoxication

Caffeine is the most widely consumed psychoactive substance worldwide. Intoxication causes central nervous system and haemodynamic complications, which have significant mortality rates. We report the case of a 39-year-old woman who ingested ∼0.5 mol (100 g) of pure caffeine, leading to a peak serum concentration of 2.95 mmol/L (574 mg/L). Three consecutive haemodialysis sessions caused serum caffeine reduction rates of 66, 46 and 45%, indicating that the unbound caffeine fraction is not dose linear in this high serum caffeine concentration range. Aggressive and repeated haemodialysis sessions may be of benefit in cases of severe caffeine intoxication.