Hexahydrocannabinol poisoning reported to French poison centres.

INTRODUCTION: Hexahydrocannabinol is a hexahydro derivative of cannabinol. Poisoning with hexahydrocannabinol was first observed in Europe in May 2022. METHOD: This is a retrospective observational study of cases of self-reported hexahydrocannabinol exposure reported to French poison centres between 1 January 2022 and 31 May 2023. RESULTS: There were 37 cases, including 19 in May 2023. The median age of the patients was 36 (interquartile range 28-43) years, and most were men. Eight patients had a history of substance use disorder. The route of exposure was ingestion in 24, inhalation (smoking or vaping) in 10, inhalation and ingestion in two and sublingual in one. Clinical features were neurological (85 per cent), cardiovascular (61 per cent), gastrointestinal (33 per cent), psychiatric (27 per cent) and ocular (21 per cent). Fifty-nine per cent of the patients were hospitalized. In four patients, the Poisoning Severity Score was 0 (asymptomatic); in 15 patients, the Score was 1 (minor); in 16, the Score was 2 (moderate); and in two cases, the Score was 3 (severe). In 70 per cent of patients, the outcome was known, and all recovered. Testing of biological samples was only undertaken in six cases. Five patients had positive blood or urine tests for hexahydrocannabinol; in two patients, tetrahydrocannabinol and metabolites were also detected. In addition, there was an additional patient in whom Δ8- and Δ9-tetrahydrocannabinol was detected in the substances used. DISCUSSION: Clinical effects reported in this series included neuropsychiatric and somatic effects. Whilst these cases related to self-reported hexahydrocannabinol use, it is likely that tetrahydrocannabinol use also contributed to the effects in a substantial proportion of cases. This study has some limitations, such as the lack of available information due to the retrospective nature of the study. As a result, it probably overestimates the number of moderate and severe cases due to under-reporting of cases of little or no severity. Analysis of the patient's blood and urine was performed only in six patients, so we cannot be certain that the products consumed by the other patients were hexahydrocannabinol. CONCLUSION: The clinical effects attributed to hexahydrocannabinol were neurological, cardiovascular, gastrointestinal, psychiatric and ocular predominantly and were sometimes serious.

Foliar application protected vegetable against poisonous element cadmium and mitigated human health risks.

Foliar application has been reported as an effective method to facilitate plant growth and mitigate cadmium (Cd) accumulation. However, the application of foliar fertilizers on plant production, Cd uptake and health risks of Solanaceae family remains unknown. In this study, four foliar fertilizers were applied to investigate their effects on the production, Cd accumulation and human health risk assessment of two varieties of pepper (Capsicum annuum L.) and eggplant (Solanum melongena L.), respectively. Compared with CK, the foliar application increased vegetable production to 104.16 %-123.70 % in peppers, and 100.83 %-105.17 % in eggplants, accordingly. The application of foliar fertilizers largely decreased Cd TF (transportation factor) by up to 23.32 % in JY, 18.37 % in GJ of pepper varieties, and up to 14.47 % in ZL, 15.24 % in HGR of eggplant varieties. Moreover, Cd BAF (bioaccumulation factor) also declined to different extents after the application of foliar fertilizers. As for human health risk assessments, foliar application diminished the hazard index (HI) and carcinogenic risk (CR) of both pepper and eggplant varieties. The results concluded that the application of composed foliar fertilizers was most effective, and could be a promising alternative for the improvement of vegetable production and mitigation of vegetable Cd accumulation and human health risks as well. The results further highlighted the understanding of foliar fertilizer application on vegetable production and health risks, which benefited better vegetable safe production and further guaranteed human health.

Nicotine and Cardiovascular Health: When Poison is Addictive - a WHF Policy Brief.

Nicotine is universally recognized as the primary addictive substance fuelling the continued use of tobacco products, which are responsible for over 8 million deaths annually. In recent years, the popularity of newer recreational nicotine products has surged drastically in many countries, raising health and safety concerns. For decades, the tobacco industry has promoted the myth that nicotine is as harmless as caffeine. Nonetheless, evidence shows that nicotine is far from innocuous, even on its own. In fact, numerous studies have demonstrated that nicotine can harm multiple organs, including the respiratory and cardiovascular systems. Tobacco and recreational nicotine products are commercialized in various types and forms, delivering varying levels of nicotine along with other toxic compounds. These products deliver nicotine in profiles that can initiate and perpetuate addiction, especially in young populations. Notably, some electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) can deliver concentrations of nicotine that are comparable to those of traditional cigarettes. Despite being regularly advertised as such, ENDS and HTP have demonstrated limited effectiveness as tobacco cessation aids in real-world settings. Furthermore, ENDS have also been associated with an increased risk of cardiovascular disease. In contrast, nicotine replacement therapies (NRT) are proven to be safe and effective medications for tobacco cessation. NRTs are designed to release nicotine in a slow and controlled manner, thereby minimizing the potential for abuse. Moreover, the long-term safety of NRTs has been extensively studied and documented. The vast majority of tobacco and nicotine products available in the market currently contain nicotine derived from tobacco leaves. However, advancements in the chemical synthesis of nicotine have introduced an economically viable alternative source. The tobacco industry has been exploiting synthetic nicotine to circumvent existing tobacco control laws and regulations. The emergence of newer tobacco and recreational nicotine products, along with synthetic nicotine, pose a tangible threat to established tobacco control policies. Nicotine regulations need to be responsive to address these evolving challenges. As such, governments should regulate all tobacco and non-medical nicotine products through a global, comprehensive, and consistent approach in order to safeguard tobacco control progress in past decades.

Assessing the frequency and types of errors involved in the use of a modified intravenous N-acetylcysteine protocol for acetaminophen overdose.

BACKGROUND: Acetaminophen overdose is a leading cause of acute liver failure in developing countries. N-acetylcysteine (NAC) is a highly effective antidote for acetaminophen hepatotoxicity, typically initiated in the emergency department. Due to a known high rate of errors with the standard three-bag IV NAC protocol, in 2019, the Ontario Poison Center changed to a modified 3% IV NAC one-bag protocol. This study was undertaken to determine the frequency and types of errors associated with the use of this protocol. METHODS: Data were gathered via chart review of Ontario Poison Centre electronic medical record cases identified as receiving IV NAC for acetaminophen overdose between August 1 and September 30, 2022. 218 total charts were identified, and 188 were deemed eligible based on inclusion and exclusion criteria. RESULTS: Errors were identified in 25% of charts, consisting of dosing errors in 11.7%, stopping errors in 9.0%, initiation errors in 3.7%, and interruptions in therapy in 3.2%. Dosing errors were the most common type of error (44.4%), with overdoses occurring three times more than underdoses. Errors were identified at 39% of geographic locations in the charts reviewed, with similar frequency in Ontario, Manitoba, and Nunavut. Clinical outcomes were similar in charts with and without errors. INTERPRETATION: The rate of errors identified with this 3% IV NAC one-bag protocol is lower than reported for the standard three-bag protocol, but remains high due to dosing errors. Previously reported issues with prolonged interruptions in therapy with the standard three-bag protocol were low with the current 3% one-bag protocol. Although severe outcomes are rare, IV NAC overdose can be fatal. Identifying local factors in emergency departments that can contribute to administration errors (i.e., dose calculation, pump programming issues) can enhance the safety of this important antidote.

RéSUMé: CONTEXTE: La surdose d'acétaminophène est l'une des principales causes d'insuffisance hépatique aiguë dans les pays en développement. La N-acétylcystéine (NAC) est un antidote très efficace contre l'hépatotoxicité de l'acétaminophène, généralement initiée au service des urgences. En raison d'un taux élevé connu d'erreurs avec le protocole NAC standard à 3 sacs IV, en 2019, le Centre antipoison de l'Ontario a adopté un protocole NAC à 1 sac IV modifié à 3 %. Cette étude a été entreprise pour déterminer la fréquence et les types d'erreurs associées à l'utilisation de ce protocole. MéTHODES: Les données ont été recueillies au moyen d'un examen des dossiers médicaux électroniques du Centre antipoison de l'Ontario qui ont reçu une dose IV de NAC pour une surdose d'acétaminophène entre le 1 août et le 30 septembre 2022. 218 cartes au total ont été identifiées, et 188 ont été jugées admissibles en fonction de critères d'inclusion et d'exclusion. RéSULTATS: Des erreurs ont été relevées dans 25 % des dossiers, soit des erreurs de dosage dans 11,7 %, des erreurs d'arrêt dans 9,0 %, des erreurs d'initiation dans 3,7 % et des interruptions du traitement dans 3,2 %. Les erreurs de dosage étaient le type d'erreur le plus courant (44,4 %), les surdoses étant trois fois plus fréquentes que les sous-doses. Des erreurs ont été relevées à 39 % des emplacements géographiques dans les cartes examinées, avec une fréquence similaire en Ontario, au Manitoba et au Nunavut. Les résultats cliniques étaient similaires dans les tableaux avec et sans erreurs. INTERPRéTATION: Le taux d'erreurs identifiées avec ce protocole à un sac NAC IV à 3 % est inférieur à celui du protocole standard à 3 sacs, mais reste élevé en raison d'erreurs de dosage. Les problèmes précédemment rapportés avec les interruptions prolongées du traitement avec le protocole standard à 3 sacs étaient faibles avec le protocole actuel à 3% à un sac. Bien que les résultats graves soient rares, une surdose de NAC IV peut être fatale. L'identification de facteurs locaux dans les services d'urgence qui peuvent contribuer aux erreurs d'administration (c.-à-d. le calcul de la dose, les problèmes de programmation de la pompe) peut améliorer l'innocuité de cet antidote important.

The 200-Year Timeline on Botulinum Toxin: From Biologic Poison to Wonder Drug.

The history of botulinum toxin dates back to the late 1700s, when food preparation, storage, and later canning practices led to outbreaks of botulism across Europe and the United States. It is from these initial incidents that the remarkable discovery of botulinum toxin was eventually made, sparking over 200 years of further scientific inquiry and medical innovation. To date, 6 botulinum toxin products have been commercialized in North America with numerous indications across the specialties of ophthalmology, neurology, urology, dermatology, plastic surgery, and otolaryngology. This article traces the key moments and important players in the remarkable journey of this biologic poison and wonder drug. J Drugs Dermatol. 2024;23(1) doi:10.36849/JDD.7288.

Cancer sensitizing effect of deazaflavin analogs is associated with increased intracellular drug accumulation.

As part of our efforts geared towards developing mechanism-based cancer sensitizing agents, we have previously synthesized and characterized novel deazaflavin analogs as potent tyrosyl DNA phosphodiesterase 2 (TDP2) inhibitors for combination treatments with topoisomerase II (TOP2) poisons. Interestingly, the sensitizing effect of a few analogs toward TOP2 poison etoposide (ETP) was associated with a significant increase in intracellular drug accumulation, which could be an alternative mechanism to boost the clinical efficacy of ETP in cancer chemotherapies. Hence, we evaluated more deazaflavin TDP2 inhibitors for their impact on drug retention in cancer cells. We found that all but one tested TDP2 inhibitors substantially increased the ETP retention in DT40 cells. Particularly, we identified an exceptionally potent analog, ZW-1226, which at 3 nM increased the intracellular ETP by 13-fold. Significantly, ZW-1226 also stimulated cellular accumulation of two other anticancer drugs, TOP2 poison teniposide and antifolate pemetrexed, and produced an effect more pronounced than those of ABC transporter inhibitors verapamil and elacridar in human leukemic CCRF-CEM cells toward ETP. Lastly, ZW-1226 potentiated the action of ETP in the sensitive human CCRF-CEM cells and a few resistant non-small-cell lung cancer (NSCLC) cells, including H460 and H838 cells. Collectively, the results of this study strongly suggest that deazaflavin analog ZW-1226 could be an effective cancer sensitizing agent which warrants further investigation.

Quenching thirst with poison? Paradoxical effect of anticancer drugs.

Anticancer drugs have been developed with expectations to provide long-term or at least short-term survival benefits for patients with cancer. Unfortunately, drug therapy tends to provoke malignant biological and clinical behaviours of cancer cells relating not only to the evolution of resistance to specific drugs but also to the enhancement of their proliferation and metastasis abilities. Thus, drug therapy is suspected to impair long-term survival in treated patients under certain circumstances. The paradoxical therapeutic effects could be described as 'quenching thirst with poison', where temporary relief is sought regardless of the consequences. Understanding the underlying mechanisms by which tumours react on drug-induced stress to maintain viability is crucial to develop rational targeting approaches which may optimize survival in patients with cancer. In this review, we describe the paradoxical adverse effects of anticancer drugs, in particular how cancer cells complete resistance evolution, enhance proliferation, escape from immune surveillance and metastasize efficiently when encountered with drug therapy. We also describe an integrative therapeutic framework that may diminish such paradoxical effects, consisting of four main strategies: (1) targeting endogenous stress response pathways, (2) targeting new identities of cancer cells, (3) adaptive therapy- exploiting subclonal competition of cancer cells, and (4) targeting tumour microenvironment.

Diverse microtubule-targeted anticancer agents kill cells by inducing chromosome missegregation on multipolar spindles.

Microtubule-targeted agents are commonly used for cancer treatment, though many patients do not benefit. Microtubule-targeted drugs were assumed to elicit anticancer activity via mitotic arrest because they cause cell death following mitotic arrest in cell culture. However, we recently demonstrated that intratumoral paclitaxel concentrations are insufficient to induce mitotic arrest and rather induce chromosomal instability (CIN) via multipolar mitotic spindles. Here, we show in metastatic breast cancer and relevant human cellular models that this mechanism is conserved among clinically useful microtubule poisons. While multipolar divisions typically produce inviable progeny, multipolar spindles can be focused into near-normal bipolar spindles at any stage of mitosis. Using a novel method to quantify the rate of CIN, we demonstrate that cell death positively correlates with net loss of DNA. Spindle focusing decreases CIN and causes resistance to diverse microtubule poisons, which can be counteracted by addition of a drug that increases CIN without affecting spindle polarity. These results demonstrate conserved mechanisms of action and resistance for diverse microtubule-targeted agents. Trial registration: clinicaltrials.gov, NCT03393741.

Developing new antidotes for poisons with existing effective treatments: a case study of fomepizole in paracetamol poisoning.

INTRODUCTION: Acetylcysteine is the only effective and licensed therapy for paracetamol poisoning. However, acetylcysteine loses efficacy if treatment is delayed 8-12 hours after paracetamol ingestion, and there is also uncertainty as to whether the dose should be increased in high-risk paracetamol ingestions. Studies have identified potential therapeutic targets, including enzymes that metabolize paracetamol; the pathways causing mitochondrial toxicity via c-Jun N-terminal kinases or superoxide generation; and other specific targets, such as nuclear factor-erythroid factor 2-dependent gene induction and autophagy. With this range of potential additional therapies, how should the speciality of clinical toxicology approach the development of new antidotes for this common poisoning? HISTORICAL BACKGROUND: When the first treatments for paracetamol toxicity were developed, the clinical trial and ethical basis of practice were different from today. Acetylcysteine was never subjected to placebo-controlled studies, even by the United States Food and Drug Administration, as it was presumed that the toxicity of high paracetamol concentrations was so evident that placebo-controlled studies were unethical. Thus, the absolute benefit of acetylcysteine remains unknown. In addition, no dose-ranging studies of acetylcysteine in patients were ever done. The weakness of assessing the efficacy of additional antidotes in small groups of patients with moderate poisoning is illustrated by the use of cimetidine in paracetamol poisoning. CURRENT APPROACHES TO DRUG (AND ANTIDOTE) DEVELOPMENT: The approach required by regulatory authorities today relies on several important steps. First, a clear target for therapeutic effect is sought, normally in a laboratory model. Next, a 'proof of principle' study is required to demonstrate that the target is 'druggable'. Finally, clinical studies to confirm proof of principle applies in humans, followed by a controlled trial with matched patient groups with sufficient power to demonstrate the clinical outcome being sought. Such patient studies can be expensive to conduct, and non-commercial groups suffer the risk of not being funded. FOMEPIZOLE: Fomepizole prevents paracetamol-induced hepatic toxicity in mice by inhibiting cytochrome P4502E1, thereby preventing the conversion of paracetamol to its toxic metabolite. Fomepizole also inhibits c-Jun N-terminal kinases, a key pathway in the downstream toxicity on the mitochondria. The present evidence of efficacy in humans is based on small case series with no control groups. The availability of a licensed indication has facilitated off-label use of fomepizole in an unproven indication. CONCLUSIONS: Paracetamol poisoning is common, and randomized, controlled clinical trials are possible. The benefit of fomepizole can only be shown by such a study. As clinical trials using fomepizole as an added therapy to acetylcysteine are recruiting in the United States, these should be supported by all clinical toxicologists. In the interim, the publication of small case series using fomepizole should be discouraged by journals.

Molecular Recognition Mechanism of an Anti-Amatoxins mAb and Its Application in Centrifugal Disk-Based Immunoassay.

Amatoxins are polypeptides that cause 90% of fatalities from accidental ingestion of poisonous mushrooms. Unfortunately, there are no specific antidotes against amatoxins poisoning, hence preparation of high-affinity antibodies, understanding the receptor (amatoxins) and ligand (antibody) mechanism, and establishing a straightforward screening approach are of great significance for confirming poison agents and clinical diagnosis. Here, anti-amatoxins monoclonal antibody (mAb) 9B2 was prepared and the recognition mechanism was investigated. The approach is useful for designing desirable immunogens, developing new antibodies with improved performance, and constructing effective immunoassays. Based on the mAb, we designed a centrifugal disk-like microfluidics chip and developed a fully automated immunoassay capable of detecting amatoxins poisoning in various samples including serum, urine, and mushrooms. The whole detection process could be automatically accomplished within 30 min, with a limit of detection of 0.08 to 0.12 µg/L for real samples, ∼30-fold more sensitive than conventional enzyme-linked immunosorbent assay (ELISA). Our platform not only provided a practical approach for performing poison agent confirmation and clinical diagnosis but also had important implications for improving the survival of patients with mushroom poisoning.

Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement.

Importance: The US and Canada currently have no formal published nationwide guidelines for specialists in poison information or emergency departments for the management of acetaminophen poisoning, resulting in significant variability in management. Objective: To develop consensus guidelines for the management of acetaminophen poisoning in the US and Canada. Evidence Review: Four clinical toxicology societies (America's Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) selected participants (n = 21). Led by a nonvoting chairperson using a modified Delphi method, the panel created a decision framework and determined the appropriate clinical management of a patient with acetaminophen poisoning. Unique to this effort was the collection of guidelines from most poison centers in addition to systematic collection and review of the medical literature. Comments from review by external organizations were incorporated before the guideline was finalized. The project began in March 2021 and ended in March 2023. Findings: The search retrieved 84 guidelines and 278 publications. The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen. In addition, the panel addressed extended-release formulation, high-risk ingestion, coingestion of anticholinergics or opioids, age younger than 6 years, pregnancy, weight greater than 100 kg, and intravenous acetaminophen use. Differences from current US practice include defining acute ingestion as an ingestion presentation from 4 to 24 hours after overdose was initiated. A revised form of the Rumack-Matthew nomogram was developed. The term massive ingestion was replaced with the term high-risk ingestion and denoted by a specific nomogram line. Other recommendations include specific criteria for emergency department triage, laboratory evaluation and monitoring parameters, defining the role of gastrointestinal decontamination, detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria for acetylcysteine treatment, as well as criteria for consultation with a clinical toxicologist. Finally, specific treatment considerations, including acetylcysteine dosing, fomepizole administration, and considerations for extracorporeal elimination and transplant evaluation, were addressed. Conclusions and Relevance: This qualitative study provides a consensus statement on consistent evidence-based recommendations for medical, pharmacy, and nursing education and practice to optimize care of patients with acetaminophen poisoning.

Continuous NO Upcycling into Ammonia Promoted by SO2 in Flue Gas: Poison Can Be a Gift.

Although ammonia (NH3) synthesis efficiency from the NO reduction reaction (NORR) is significantly promoted in recent years, one should note that NO is one of the major air pollutants in the flue gas. The limited NO conversion ratio is still the key challenge for the sustainable development of the NORR route, which potentially contributes more to contaminant emissions rather than its upcycling. Herein, we provide a simple but effective approach for continuous NO reduction into NH3, promoted by coexisting SO2 poison as a gift in the flue gas. It is significant to discover that SO2 plays a decisive role in elevating the capacity of NO absorption and reduction. A unique redox pair of SO2-NO is constructed, which contributes to the exceptionally high conversion ratio for both NO (97.59 ± 1.42%) and SO2 (99.24 ± 0.49%) in a continuous flow. The ultrahigh selectivity for both NO-to-NH3 upcycling (97.14 ± 0.55%) and SO2-to-SO42- purification (92.44 ± 0.71%) is achieved synchronously, demonstrating strong practicability for the value-added conversion of air contaminants. The molecular mechanism is revealed by comprehensive in situ technologies to identify the essential contribution of SO2 to NO upcycling. Besides, realistic practicality is realized by the efficient product recovery and resistance ability against various poisoning effects. The proposed strategy in this work not only achieves a milestone efficiency for NH3 synthesis from the NORR but also raises great concerns about contaminant resourcing in realistic conditions.

Multiple Routes to Color Convergence in a Radiation of Neotropical Poison Frogs.

Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, "reddish" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms.

Old poisons, new signaling molecules: the case of hydrogen cyanide.

The high phenotypic plasticity developed by plants includes rapid responses and adaptations to aggressive or changing environments. To achieve this, they evolved extremely efficient mechanisms of signaling mediated by a wide range of molecules, including small signal molecules. Among them, hydrogen cyanide (HCN) has been largely ignored due to its toxic characteristics. However, not only is it present in living organisms, but it has been shown that it serves several functions in all kingdoms of life. Research using model plants has changed the traditional point of view, and it has been demonstrated that HCN plays a positive role in the plant response to pathogens independently of its toxicity. Indeed, HCN induces a response aimed at protecting the plant from pathogen attack, and the HCN is provided either exogenously (in vitro or by some cyanogenic bacteria species present in the rhizosphere) or endogenously (in reactions involving ethylene, camalexin, or other cyanide-containing compounds). The contribution of different mechanisms to HCN function, including a new post-translational modification of cysteines in proteins, namely S-cyanylation, is discussed here. This work opens up an expanding 'HCN field' of research related to plants and other organisms.

Animal Toxins: A Historical Outlook at the Institut Pasteur of Paris.

Humans have faced poisonous animals since the most ancient times. It is recognized that certain animals, like specific plants, produce toxic substances that can be lethal, but that can also have therapeutic or psychoactive effects. The use of the term "venom", which initially designated a poison, remedy, or magic drug, is now confined to animal poisons delivered by biting. Following Louis Pasteur's work on pathogenic microorganisms, it was hypothesized that venoms could be related to bacterial toxins and that the process of pathogenicity attenuation could be applied to venoms for the prevention and treatment of envenomation. Cesaire Phisalix and Gabriel Bertrand from the National Museum of Natural History as well as Albert Calmette from the Institut Pasteur in Paris were pioneers in the development of antivenomous serotherapy. Gaston Ramon refined the process of venom attenuation for the immunization of horses using a formalin treatment method that was successful for diphtheria and tetanus toxins. This paved the way for the production of antivenomous sera at the Institut Pasteur, as well as for research on venom constituents and the characterization of their biological activities. The specific activities of certain venom components, such as those involved in blood coagulation or the regulation of chloride ion channels, raises the possibility of developing novel therapeutic drugs that could serve as anticoagulants or as a treatment for cystic fibrosis, for example. Scientists of the Institut Pasteur of Paris have significantly contributed to the study of snake venoms, a topic that is reported in this review.