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Background: Acetaminophen toxicity remains one of the most common causes of liver failure and is treated with a course of n-acetylcysteine (NAC). This exceptionally effective medication is traditionally administered using a complicated three-bag protocol that is prone to administration errors., Objective: We aimed to assess whether switching to a novel two-bag protocol (150 mg/kg over 1 h followed by 150 mg/kg over 20 h) reduced administration errors while not increasing liver injury or anaphylactoid reactions., Methods: This was a retrospective chart review of hospital encounters for patients with acetaminophen toxicity, comparing outcomes before and after the change from a three-bag protocol to a two-bag protocol at two affiliated institutions. The primary outcome was incidence of medication errors with secondary outcomes including acute liver injury (ALI) and incidence of non-anaphylactoid allergic reactions (NAAR). The study was approved by the health system's Institutional Review Board., Results: 483 encounters were included for analysis (239 in the three-bag and 244 in the two-bag groups). NAAR were identified in 11 patients with no difference seen between groups. Similarly, no differences were seen in ALI. Medication administration errors were observed significantly less often in the two-bag group (OR 0.24) after adjusting for confounders., Conclusion: Transitioning to a novel two-bag NAC regimen decreased administration errors. This adds to the literature that two-bag NAC regimens are not only safe but also may have significant benefits over the traditional NAC protocol., (© 2024. American College of Medical Toxicology.)

Introduction: Physostigmine fell out of widespread use in the 1980s due to safety concerns; however, more recent research has demonstrated that its safety profile is better than previously thought. These studies have mainly included adults. We theorized that improved safety data may lead to more acceptance. Our objectives, therefore, were to characterize current frequency of use of physostigmine in pediatric patients as well as to study adverse effect rates in a national pediatric patient population., Methods: The National Poison Data System was queried for cases of patients aged 0-18 years that involved single-substance exposures to antimuscarinic xenobiotics that were reported to a poison center between January 1, 2000, and December 31, 2020. Cases were stratified into groups by therapy received: benzodiazepines alone, benzodiazepines and physostigmine, physostigmine alone, or no physostigmine or benzodiazepines. Patient demographics, clinical effects, and medical outcomes were analyzed., Results: A total of 694,132 cases were reviewed, and 150,075 were included for analysis. Nearly 5% (7562/150,075) of patients received specific pharmacological therapy with benzodiazepines, physostigmine, or both. A benzodiazepine as a single agent was the most frequently used pharmacologic therapy (92% of 7562). Among patients receiving any pharmacological therapy, only 8.3% (n = 627) of patients received physostigmine. Frequency of serious outcomes significantly increased across the study period among patients receiving benzodiazepines alone or with physostigmine. There was no increase in serious outcomes among patients receiving only physostigmine., Conclusions: Physostigmine frequency of use was low overall, but when used, was associated with less severe outcomes when compared to benzodiazepines., (© 2024. American College of Medical Toxicology.)

Introduction: Children are at higher risk of medication errors due to the complexity of drug prescribing and administration in this patient group. Intravenous (IV) paracetamol overdose differs from overdose by ingestion as there is no enteral absorptive buffering. We provide the first national UK data focusing on paediatric IV paracetamol poisoning., Methods: All telephone enquiries to the National Poisons Information Service between 2008 and 2021 regarding children less than 18 years old in the UK concerning IV paracetamol overdose were extracted from the UK Poisons Information Database (UKPID). Data were analysed using descriptive statistics., Results: Enquiries were made concerning 266 children, mostly involving children under the age of 1 year (n=145; 54.5%). Acute and staggered overdoses were the most frequent types of exposure. Common error themes included 10-fold overdose in 45 cases (16.9%) and inadvertent concomitant oral and IV dosing in 64 cases (24.1%). A high proportion of cases were asymptomatic (87.1%), with many calls regarding overdoses below the treatable dose of 60 mg/kg (41.4%). Treatment with the antidote acetylcysteine was advised in 113 cases (42.5%)., Conclusions: Inadvertent IV paracetamol overdose appears to occur more frequently in young children. A significant proportion were calculation errors which were often 10-fold errors. While these errors have the potential for causing serious harm, thankfully most cases were asymptomatic. Errors with IV paracetamol might be reduced by electronic prescribing support systems, better communication regarding administration and consideration of whether other routes are more appropriate., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

And Then There Were None and Sparkling Cyanide, two of Agatha Christie's famous novels describe potassium cyanide-induced deaths. Cyanide, a tasteless, odorless, strongly alkaline poison is a powerful gastrointestinal irritant, following oral ingestion. It reacts with hydrochloric acid in the gastric juice to produce hydrogen cyanide gas, which is absorbed and inhibits the mitochondrial electron transfer system and consequently suppresses adenosine triphosphate (ATP) production. Therefore, the central nervous system, which consumes a large amount of ATP, is first affected and symptoms of poisoning manifest as dizziness, disorientation, coma, and convulsions. The orally lethal dose is approximately 300 mg.

BACKGROUND ThinPrep Cytolyt is a methanol-based cell preservation solution frequently used to fix tissue samples immediately following endobronchial ultrasound-guided fine-needle aspiration. Currently, no published reports describe an iatrogenic exposure to Cytolyt. We report the only known case of an accidental intraoperative administration of a methanol solution, with corresponding plasma concentrations, and successful treatment with fomepizole. CASE REPORT A 70-year-old woman with a history of stage IIIA rectal adenocarcinoma was referred for evaluation of a newly identified lung mass. During the procedure, a bronchoalveolar lavage (BAL) of the right upper lobe was performed. After BAL, the proceduralist was informed that the syringe used to instill fluid for the BAL contained Cytolyt rather than saline. The Department of Medical Toxicology was contacted immediately, and the patient received a 15 mg/kg dose of fomepizole. The first plasma methanol level, before fomepizole administration, was elevated to 21 mg/dL. The methanol level was 13 mg/dL 3 h after fomepizole treatment and even lower thereafter; therefore, no additional fomepizole was required. The patient did not develop signs of systemic toxicity and was discharged on hospital day 3. CONCLUSIONS Following methanol exposures, patients can exhibit metabolic acidosis, with potential for blindness, hemodynamic instability, and possibly death if untreated. Fomepizole (4-methylpyrazole) inhibits alcohol dehydrogenase and is a mainstay of treatment. Preventing medical errors is key in ensuring optimal patient care and decreasing adverse events. Providers using CytoLyt and any similar products should be aware of this potential error and approach the possibility of methanol toxicity as they would other routes of methanol exposure.

Background: Historically, the first step in treating cyanide (CN - ) toxicity utilized antidotes to induce methemoglobinemia. This is concerning in patients who are already hypoxemic or have elevated carboxyhemoglobin. Hydroxocobalamin (OHCbl) is now the first-line antidote for CN - toxicity and is not known to induce methemoglobinemia. We observed elevated methemoglobin (MetHb) levels in several patients treated with OHCbl and sought to investigate the incidence of MetHb formation following administration of OHCbl., Methods: Chart review: A single-center, retrospective case series of patients who received 5 or 10 g of hydroxocobalamin from 01/01/2011 through 04/30/2019. Data was analyzed using descriptive statistics. In-vitro study: Discarded blood was separated into whole blood and plasma samples. OHCbl and normal saline was added to reach 0×, 1×, 2×, and 4× peak therapeutic concentrations and analyzed at times 0, 2, and 4 h after administration., Results: Chart review : Twenty-seven cases of OHCbl administration were identified. The median age was 53 years (IQR 38 - 64) and 20 (74.1%) were male. Exposure to a house fire or smoke inhalation was the reason for OHCbl administration in 21 (77.8%) patients. Five (18.5%) patients received 10 g of OHCbl while the rest received 5 g. Six (22.2%) patients developed methemoglobinemia, all after 5 g OHCbl administration; four had been exposed to fire and smoke, two received the medication for severe acidosis of unknown etiology not related to fire or smoke. The median peak level was 7.1% (IQR 2.2 - 16.4%) at a median time of 11.4 h post-administration. Two patients received methylene blue (MB), neither responded. Death occurred in 17 (63%) cases. In-vitro study: We observed a dose dependent elevation in total hemoglobin but did not detect any increase in MetHb., Conclusion: We observed a noteworthy temporal association between the formation of methemoglobinemia and the administration of hydroxocobalamin. This does not appear to be an artifact of the CO-oximeters. This could have profound implications for patients who are already hypoxemic or have impaired oxygen carrying capacity from carboxyhemoglobin.

Introduction: Although not a potentially life-threatening poisoning, benzodiazepine (BZD) intoxication may be life-threatening in special situations/populations or those with background diseases., Areas Covered: The aim of this review is to evaluate all possible treatment options available in the literature for the management of benzodiazepine poisoning with special attention to antidote administration. We conducted a literature search using PubMed, Google Scholar, EMBASE, and Cochrane central register from 1 January 1980 to 10 November 2021 using keywords 'benzodiazepine,' 'poisoning,' 'toxicity,' 'intoxication,' and 'treatment.', Expert Opinion: Careful patient selection, ideally by a clinical toxicologist, may decrease the complications of flumazenil and add to its efficacy. The cost-to-benefit ratio should be considered in every single patient who is a candidate for flumazenil administration. In case a decision has been made to administer flumazenil, careful consideration of the possible contraindications is essential. We recommend slow administration of low doses of flumazenil (0.1 mg/minute) to avoid complications or withhold the administration with development of first signs of adverse effects. The main treatment of benzodiazepine toxicity is conservative with administration of activated charcoal, monitoring of the vital signs, prevention of aspiration and development of deep vein thrombosis due to prolonged immobilization, and respiratory support.

Introduction: Acetylcysteine is the standard treatment for preventing hepatotoxicity caused by acetaminophen overdose. Several novel approaches to the management of acetaminophen overdose have been suggested to improve patient safety by reducing adverse drug reactions and dosing errors. This article reviews these alternative treatment regimens and intends to offer a detailed assessment of the available options to assist providers in managing cases of acetaminophen overdose., Areas Covered: This review article covers observational and experimental studies that assessed the efficacy and safety of alternative intravenous acetylcysteine regimens for acetaminophen overdose. A literature search was conducted using PubMed, ProQuest, and Scopus to identify the studies, which included results through April 2021. The assessment of alternative regimens consists of a discussion on the limitations and benefits, barriers to implementation, and important considerations for each regimen., Expert Opinion: Several alternative regimens have been studied and implemented in various institutions. Many of these dosing regimens have supporting safety data but most lack robust data. A reduction in infusion-related side effects is an important outcome, but established efficacy, local poison center familiarity with the regimen, institutional resources, and patient-specific factors should be equally considered when deciding on implementing and using an alternative dosing strategy.

Copper sulfate immersion is common for the prevention and treatment of Cryptocaryon irritans during quarantine of marine teleosts. The National Aquarium in Baltimore has followed a consistent copper sulfate protocol for marine teleost quarantine since 2004. The protocol used copper sulfate pentahydrate as a slow drip to increase copper ions over 3-5 days to a level of 0.18-0.21 mg/L. This level was maintained for 21 days, and then copper ions were rapidly removed with activated carbon filtration and water changes. Quarantine records from 2004-2016 were used to examine mortality of marine teleosts during copper treatment and identify factors that might have influenced mortality. The following records were excluded: brackish and freshwater teleosts (salinity <25 g/L); long-term treatment at subtherapeutic levels (<0.18 mg/L); intentional short courses (<14 days); and use outside of quarantine. Species, system volume, temperature, parasitic outbreaks, concurrent medications, and water quality concerns were evaluated. During this period, 4,835 individual teleosts belonging to 347 different species were treated. From 2004 to 2016, mortality during copper treatment was 4.1% (199/4,835 individuals) and was higher when treatment was started during the first week of quarantine (7.7%, 68/884) rather than later (3.3%, 131/3,951 individuals). Of the mortalities, 24.1% (48/199) occurred during the initial subtherapeutic period, and 75.9% (151/199) occurred during the therapeutic period. No mortalities occurred in 75.5% (262/347) of species during copper treatment. When using a similar methodology, copper sulfate is a safe immersion for quarantine of marine teleosts. Mortalities during copper treatment can be reduced by increasing copper ion levels to therapeutic ranges more slowly (e.g., over 7 days) and starting copper treatment after the first week of quarantine.

Background: Sodium bicarbonate therapy (SBT) is currently indicated for the management of a variety of acute drug poisonings. However, SBT effects on serum potassium concentrations may lead to delayed QTc prolongation (DQTP), and subsequent risk of adverse cardiovascular events (ACVE), including death. Emergency department (ED)-based studies evaluating associations between SBT and ACVE are limited; thus, we aimed to investigate the association between antidotal SBT, ECG changes, and ACVE., Methods: This was a secondary data analysis of a consecutive cohort of ED patients with acute drug overdose over 3 years. Demographic and clinical data as well as SBT bolus dosage and infusion duration were collected, and outcomes were compared with an unmatched consecutive cohort of patients with potential indications for SBT but who did not receive SBT. The primary outcome was the occurrence of ACVE, and secondary outcomes were delayed QTc (Bazett) prolongation (DQTP), and death. Propensity score and multivariable adjusted analyses were conducted to evaluate associations between adverse outcomes and SBT administration. Planned subgroup analysis was performed for salicylates, wide QRS (> 100 ms), and acidosis (pH < 7.2)., Results: Out of 2365 patients screened, 369 patients had potential indications for SBT, of whom 31 (8.4%) actually received SBT. In adjusted analyses, SBT was found to be a significant predictor of ACVE (aOR 9.35, CI 3.6-24.1), DQTP (aOR 126.7, CI 9.8-1646.2), and death (aOR 11.9, CI 2.4-58.9). Using a propensity score model, SBT administration was associated with ACVE (OR 5.07, CI 1.8-14.0). Associations between SBT and ACVE were maintained in subgroup analyses of specific indications for sodium channel blockade (OR 21.03, CI 7.16-61.77) and metabolic acidosis (OR: 6.42, 95% CI: 1.20, 34.19)., Conclusion: In ED patients with acute drug overdose and potential indications for SBT, administration of SBT as part of routine clinical care was an independent, dose-dependent, predictor of ACVE, DQTP, and death. This study was not designed to determine whether the SBT or acute overdose itself was causative of ACVE; however, these data suggest that poisoned patients receiving antidotal SBT require close cardiovascular monitoring.

Activated charcoal (AC) is a potential candidate antidote against dioxins. However, it is difficult to take AC as a supplement on a daily basis, because its long-term ingestion causes side effects such as constipation and deficiency of fat-soluble essential nutrients and hypocholesterolemia. Alginate-coated AC, termed Health Carbon (HC), was developed to decrease the side effects of AC, but its pharmacological effects, including side effects, remains unclear. Here, we show that HC enhanced fecal excretion of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and decreased some side effects of unmodified AC, such as hypocholesterolemia, in male mice. Basal diet mixed with HC or unmodified AC at various concentrations was fed to mice for 16 days following a single intraperitoneal administration of [ 3 H]TCDD. Both HC and unmodified AC at 3% or more significantly increased fecal excretion of [ 3 H]TCDD in comparison with the control basal diet. Consistent with this, [ 3 H]TCDD radioactivity in the liver-a major TCDD storage organ-was markedly decreased by HC at concentrations of 3% and 10%. In an examination of potential side effects, unmodified AC at 10% or more caused significant body weight reduction and at 20% caused significant hypocholesterolemia. In contrast, HC caused weight gain reduction only at a concentration of 20%, and there was no evidence of hypocholesterolemia at any dietary HC concentration. HC not only retains the ability of AC to enhance fecal excretion of TCDD but also reduces some of the side effects of AC.

Abstract: Although using direct oral anticoagulants increases patient risk for hemorrhagic events, FDA-approved options for reversing anticoagulant effects are limited. This article discusses one of the more recent FDA-approved antidotes, andexanet alfa, and provides guidelines for its safe and effective use., (Copyright © 2021 American Academy of Physician Assistants.)

Intravenous lipid emulsion (ILE) is a widely accepted treatment for local anesthetic systemic toxicity (LAST), particularly resulting from bupivacaine. The past decade has seen interest in antidotal use of ILE for other poisonings wax and wane. Numerous anecdotes have raised enthusiasm while more rigorous reviews have cast skepticism. The truth may lie between these two poles.We illustrate the recent trends in published reports on ILE. We highlight the gaps in our knowledge and suggest sources of data that may clarify how useful ILE may be for poisonings other than LAST. We offer the example of bupropion, which is hazardous in overdose and which has a Log P (octanol-water partition coefficient) similar to that of bupivacaine.Current data sources including the AAPCC National Poison Data System (NPDS), the ACMT Toxic Investigators Consortium (ToxIC), and a voluntary online registry (www.lipidrescue.org) each give an incomplete view of the problem. We propose analysis of newer NPDS data, which will include ILE as a treatment field code beginning with the 2019 data, and a structured, prospective registry of antidotal use of ILE for poisonings other than LAST.

Introduction: Direct thrombin inhibitor, dabigatran and factor Xa inhibitors, apixaban, edoxaban, and rivaroxaban (DOACs/NOACs), are currently the first-choice drugs in some indications. Life-threatening bleeding occurring during DOACs treatment may benefit from the use of reversal agents, however there are some concerns regarding potential rebound thrombotic events. In this systematic review we aimed to estimate the incidence of thrombotic events in patients treated with idarucizumab or andexanet alfa., Methods: This systematic review included all prospective and retrospective studies, enrolling patients that received specific antidotes (idarucizumab, andexanet alfa and cirapantag) for anticoagulation reversal, published until October 2019 in CENTRAL, MEDLINE and PsycINFO. Studies in healthy individuals and those with less than 10 patients were excluded. The primary outcome was the incidence of thrombotic events and the secondary outcome was all-cause mortality. Studies screening and data extraction was performed in duplicate by reviewers. A random-effects meta-analysis was performed using the Freeman-Tukey transformation of the data. The results are expressed in percentages, with 95%-confidence intervals (CI), limited between 0 and 100% due to the data transformation., Results: Overall 16 studies with 1774 patients were included (13 studies enrolling 1384 patients that received idarucizumab; 3 studies enrolling 390 patients that received andexanet alfa; cirapantag studies were not found). The pooled incidence rate of thrombotic events in the patients treated with specific antidote was 5.5% (95% CI 2.0-10.1%) until 30-90 days. The incidence of all-cause mortality was 13.3% (95% CI 9.6-17.5%)., Conclusions: In patients requiring idarucizumab or andexanet alfa to reach haemostasis, our data shows that there were 5.5% thrombotic events. The causality of harm associated to antidotes remains to be established due to the design of studies without a control group., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Acetaminophen (APAP) hepatotoxicity is the leading cause of acute liver failure in the western world. Despite extensive investigations into the mechanisms of cell death, only a single antidote, N-acetylcysteine, is in clinical use. However, there have recently been more efforts made to translate mechanistic insight into identification of therapeutic targets and potential new drugs for this indication., Areas Covered: After a short review of the key events in the pathophysiology of APAP-induced liver injury and recovery, the pros and cons of targeting individual steps in the pathophysiology as therapeutic targets are discussed. While the re-purposed drug fomepizole (4-methylpyrazole) and the new entity calmangafodipir are most advanced based on the understanding of their mechanism of action, several herbal medicine extracts and their individual components are also considered., Expert Opinion: Fomepizole (4-methylpyrazole) is safe and has shown efficacy in preclinical models, human hepatocytes and in volunteers against APAP overdose. The safety of calmangafodipir in APAP overdose patients was shown but it lacks solid preclinical efficacy studies. Both drugs require a controlled phase III trial to achieve regulatory approval. All studies of herbal medicine extracts and components suffer from poor experimental design, which questions their clinical utility at this point.

Purpose: Drug-induced liver injury (DILI) that progresses to acute liver failure (ALF) has a high mortality rate, and therapeutic options are limited. Acetylcysteine has a labeled indication for use as an antidote for acetaminophen toxicity and has also been used with limited success in treatment of non-acetaminophen-induced liver injury, with small clinical trials indicating an increase in transplant-free survival. Recommendations for management of non-acetaminophen-induced DILI include withdrawal of the offending agent and supportive care. Treatment guidelines generally discourage a rechallenge with an offending medication, except in cases where there are no other therapeutic options for management of a serious disease, such as active tuberculosis (TB)., Summary: This case report describes the reversal of ALF due to DILI in a patient receiving antitubercular agents for active TB. After withdrawal of initially prescribed antitubercular agents, the patient was switched to a less hepatotoxic anti-TB regimen and intravenous acetylcysteine pending results of antimicrobial susceptibility testing. After stabilization of the patient's liver enzyme levels, intravenous acetylcysteine was discontinued and oral acetylcysteine was continued for 5 days without an increase in hepatic enzyme levels or clinical deterioration. After 5 days, oral acetylcysteine was discontinued due to patient-reported nausea and vomiting., Conclusion: Given the limited number of therapeutic interventions shown to be beneficial in ALF and data suggesting a protective effect against DILI with initiation of acetylcysteine at the start of treatment with anti-TB medications, acetylcysteine can be considered for patients with anti-TB - associated DILI., (© American Society of Health-System Pharmacists 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Disulfiram-ethanol reaction (DER) due to acetaldehyde accumulation occurs after drinking ethanol during disulfiram therapy. DER may result in life-threatening toxicity requiring urgent critical care. Fomepizole, an alcohol dehydrogenase inhibitor used to treat toxic alcohol poisoning, has been suggested for treating DER by preventing the metabolism of ethanol to acetaldehyde. However, its effectiveness and safety have been poorly assessed in this setting. Cases: Ten DER patients (median age, 40 years; 7 males/3 females) were included in the study. DER features consisted of consciousness impairment (median Glasgow coma score, 13; need for mechanical ventilation, 30%) with flushing (50%), vomiting (40%), electrocardiogram abnormalities (30%) and circulatory failure requiring norepinephrine (30%). Patients were successfully treated with a single intravenous infusion of fomepizole (median dose, 7.5 mg/kg). The three patients receiving norepinephrine did not improve until fomepizole was administered. The other seven patients improved promptly following fomepizole infusion without requirement for vasopressor support. All patients fully recovered. Local pain at the injection site was the only reported adverse reaction in one patient. Conclusion: Our case series supports the effectiveness and safety of fomepizole in rapidly reversing DER-induced vasodilatation and toxicity.

Organophosphorus (OP) pesticides and nerve agents still pose a threat to the population. Treatment of OP poisoning is an ongoing challenge and burden for medical services. Standard drug treatment consists of atropine and an oxime as reactivator of OP-inhibited acetylcholinesterase and is virtually unchanged since more than six decades. Established oximes, i.e. pralidoxime, obidoxime, TMB-4, HI-6 and MMB-4, are of insufficient effectiveness in some poisonings and often cover only a limited spectrum of the different nerve agents and pesticides. Moreover, the value of oximes in human OP pesticide poisoning is still disputed. Long-lasting research efforts resulted in the preparation of countless experimental oximes, and more recently non-oxime reactivators, intended to replace or supplement the established and licensed oximes. The progress of this development is slow and none of the novel compounds appears to be suitable for transfer into advanced development or into clinical use. This situation calls for a critical analysis of the value of oximes as mainstay of treatment as well as the potential and limitations of established and novel reactivators. Requirements for a straightforward identification of superior reactivators and their development to licensed drugs need to be addressed as well as options for interim solutions as a chance to improve the therapy of OP poisoning in a foreseeable time frame.

Introduction: Fomepizole has been recommended as first-line antidote to treat ethylene glycol and methanol poisoning. Despite more than 30 years of utilization, the safety of fomepizole when used clinically has not been well documented. Based on the long-standing clinical experience with fomepizole in France, we investigated its safety profile in patients treated for suspected toxic alcohol poisoning. Methods: We designed a 16-year post-marketing study to evaluate the indications for fomepizole prescriptions and to investigate its safety. Data were retrospectively collected using a standardized questionnaire sent each month by post to each French hospital that ordered fomepizole during the month before. The response rate to our survey was 59%. Results: Five hundred and thirty-six patients [188 females/348 males; age, 46 years [34-55] (median [25th-75th percentiles])] were treated with fomepizole [cumulative dose, 18.6 mg/kg [15.5-26.3] (1,268 mg [900-2,100])]. Ethylene glycol/methanol poisoning was confirmed in 275 patients (51%) while a nontoxic exposure was diagnosed in 147 patients (27%). Toxic alcohol poisoning was misdiagnosed in the remaining 114 patients (21%), before the assessment of an alternative poisoning or non-poisoning diagnosis. Fifty adverse reactions were attributed to fomepizole in 36 patients (7%) including general reactions ( N  = 22), local reactions ( N  = 22) and laboratory test impairments ( N  = 6). All were considered mild and transient. None required stopping fomepizole. The most frequent adverse effects were injection site pain/burning ( N  = 13), nausea/vomiting ( N  = 8), vessel puncture site inflammation ( N  = 7), drowsiness/confusion ( N  = 5) and serum aminotransferase elevation ( N  = 3). None of the fatalities ( N  = 37, 7%) or persistent symptoms on discharge ( N  = 9; 2%) was related to fomepizole. Conclusion: Our longitudinal cohort study supports the safety of fomepizole administered to treat presumed EG and methanol poisoning.

Context: N -acetylcysteine (NAC) is used worldwide to prevent liver injury after paracetamol overdoses. Anaphylactoid reactions to NAC occur frequently and often lead to treatment interruptions or discontinuations. In Denmark in 2013, the NAC treatment regimen was simplified from a three-bag to a two-bag NAC regimen. Factors of importance for the development of anaphylactoid reaction to this new regimen are poorly explored. Previous studies have suggested a protective effect of high plasma levels of paracetamol on the development of anaphylactoid reactions. Likewise, exposure to antihistamines prior to NAC treatment may protect against these reactions. Methods: This is a retrospective cohort study of patients treated with NAC and with at least one plasma paracetamol sample performed in the Capital Region of Denmark from 2010 to 2017. The primary outcome was the incidence of anaphylactoid reactions to NAC requiring intravenous treatment with antihistamines and/or glucocorticoids. Logistic regression analyses were carried out to identify the risk of developing an anaphylactoid reaction to NAC affected by influencing factors. Results: Of 4315 admissions included in the study, 259 (6.0%) developed an anaphylactoid reaction to NAC. The two-bag regimen (adjusted OR 0.44 [95%CI: 0.32-0.60]), increasing age (adjusted OR 0.84 [95%CI: 0.78-0.90] per 10-year increase) or children <10 years (adjusted OR 0.14 [95%CI: 0.04-0.36]) and antihistamine co-ingestion in overdose (adjusted OR 0.17 [95%CI: 0.02-0.64]) were associated with significantly fewer anaphylactoid reactions. High plasma paracetamol concentrations protected against development of anaphylactoid reactions during the two-bag regimen (adjusted OR 0.59 [95%CI: 0.47-0.71] and three-bag regimen 0.82 [95%CI: 0.72-0.94] per doubling of paracetamol concentration). The effect differed between the two regimens ( p  = .004 for interaction). Conclusion: In this retrospective cohort, a high peak plasma paracetamol concentration, age, antihistamine co-ingestion and use of the two-bag NAC regimen were associated with fewer anaphylactoid reactions to NAC.

Arsenic (As) is widely used in the modern industry, especially in the production of pesticides, herbicides, wood preservatives, and semiconductors. The sources of As such as contaminated water, air, soil, but also food, can cause serious human diseases. The complex mechanism of As toxicity in the human body is associated with the generation of free radicals and the induction of oxidative damage in the cell. One effective strategy in reducing the toxic effects of As is the usage of chelating agents, which provide the formation of inert chelator-metal complexes with their further excretion from the body. This review discusses different aspects of the use of metal chelators, alone or in combination, in the treatment of As poisoning. Consideration is given to the therapeutic effect of thiol chelators such as meso-2,3-dimercaptosuccinic acid, sodium 2,3-dimercapto-1-propanesulfonate, 2,3-dimercaptopropanol, penicillamine, ethylenediaminetetraacetic acid, and other recent agents against As toxicity. The review also considers the possible role of flavonoids, trace elements, and herbal drugs as promising natural chelating and detoxifying agents.

Background: Clinical experience with using activated prothrombin complex concentrates (aPCCs) to reverse the effects of factor Xa inhibitors is limited., Objectives: Our objective was to assess the achievement of effective clinical hemostasis using aPCC in patients on chronic apixaban or rivaroxaban therapy presenting with major bleeding in whom a reversal agent is warranted. We also assessed the safety of the drug., Methods: A retrospective medical records review was conducted at a tertiary referral medical center in the USA. Patients presenting with major bleeding while receiving apixaban or rivaroxaban and treated with aPCC were included. Clinical hemostasis was assessed using International Society of Thrombosis and Hemostasis Scientific and Standardization Subcommittee criteria., Results: A total of 35 patients were included in the study. The most common site of bleeding was intracerebral hemorrhage (ICH) (n = 18 [51.4%]), followed by gastrointestinal bleed (n = 10 [28.6%]). Clinical hemostasis was achieved in 24 (68.6%) patients; 11 patients (31.4%) did not achieve clinical hemostasis; nine of these patients had ICH. Seven of the patients who did not achieve hemostasis died during hospitalization. Three (8.6%) patients experienced thromboembolic events during hospitalization. In total, 21 (60%) patients were receiving concomitant medications that interact with anti-factor Xa inhibitors and can increase the risk of bleeding., Conclusions: Our study suggests that aPCC could be an option in patients with major bleeding associated with apixaban or rivaroxaban. It may be an alternative for patients who need anticoagulation reversal if the specific antidote, andexanet alfa, is unavailable.

Poisoning is the greatest source of avoidable death in the world and can result from industrial exhausts, incessant bush burning, drug overdose, accidental toxication or snake envenomation. Since the advent of Albert Calmette's cobra venom antidote, efforts have been geared towards antidotes development for various poisons to date. While there are resources and facilities to tackle poisoning in urban areas, rural areas and developing countries are challenged with poisoning management due to either the absence of or inadequate facilities and this has paved the way for phyto-antidotes, some of which have been scientifically validated. This review presents the scope of antidotes' effectiveness in different experimental models and biotechnological advancements in antidote research for future applications. While pockets of evidence of the effectiveness of antidotes exist in vitro and in vivo with ample biotechnological developments, the utilization of analytic assays on existing and newly developed antidotes that have surpassed the proof of concept stage, as well as the inclusion of antidote's short and long-term risk assessment report, will help in providing the required scientific evidence(s) prior to regulatory authorities' approval.

Oral anticoagulants, old and new, are effective therapies for prevention and treatment of venous thromboembolism and reduction of stroke risk in patients with atrial fibrillation. However, blocking elements of the clotting cascade carries an inherent risk of bleeding. Also, anticoagulated patients sometimes require urgent surgery or invasive procedures. This has led to the emergence of a body of scientific literature on the reversal of anticoagulation in these two settings. Traditionally, vitamin K antagonists (VKAs), which indirectly inactivate clotting factors II, VII, IX and X (and natural anticoagulant proteins C and S), had been the mainstay of oral anticoagulation for half a century. Only a few years ago, the US Food and Drug Administration (FDA) approved a specific VKA reversal agent, 4-Factor Prothrombin Complex Concentrate (4F-PCC). The last decade has seen the rise of non-Vitamin K oral anticoagulants (NOACs), which target specific factors, i.e. Factors IIa and Xa. Investigators have rapidly developed reversal agents for these agents as well, idarucizumab for the Factor IIa inhibitor dabigatran (Pradaxa) and andexanet alfa for the entire class of Factor Xa inhibitors (FXaIs), currently four drugs: rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and betrixaban (Bevyxxa). Clinicians still use off-label PCC for reversing FXaIs in some settings, and a universal reversal agent, ciraparantag, remains in development. This review summarizes the safety and efficacy of these reversal agents in the setting of anticoagulant-associated major bleeding and the need for urgent surgery., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The primary goal of this work was to develop a computational tool to enable personalized prediction of pharmacological disposition and associated responses for opioids and antidotes. Here we present a computational framework for physiologically-based pharmacokinetic (PBPK) modeling of an opioid (morphine) and an antidote (naloxone). At present, the model is solely personalized according to an individual's mass. These PK models are integrated with a minimal pharmacodynamic model of respiratory depression induction (associated with opioid administration) and reversal (associated with antidote administration). The model was developed and validated on human data for IV administration of morphine and naloxone. The model can be further extended to consider different routes of administration, as well as to study different combinations of opioid receptor agonists and antagonists. This work provides the framework for a tool that could be used in model-based management of pain, pharmacological treatment of opioid addiction, appropriate use of antidotes for opioid overdose and evaluation of abuse deterrent formulations.

Since the late 1970s N-acetylcystein has been used as an antidote after paracetamol intoxication. The treatment is traditionally given as three consecutive infusions for 20 hours and 15 minutes. The total dose given is 300 mg/kg. Half of this amount is given as a bolus during the first 15 minutes of treatment.  This regime has proven very efficient in avoiding liver injury. However, side effects, caused by histamine release, are common (10-15%). Symptoms as flush, urticaria and, in rare cases, bronchospasm, angioedema and circulatory shock typically appear during the bolus dose and may lead to interrupted and inadequate treatment. In addition, the regime is complicated leading to a risk of administration errors. During the last years several publications have described the use of a model with two infusions instead of three. The first and the second infusions are merged and given over four hours. The third infusion and the total dose are left unchanged. This modified regime has been shown to reduce side effects and seems not to increase the risk of liver injury. As of November 1, 2019, the Swedish Poisons Information Centre will change its recommendations to the new two-infusion protocol.

Sodium cyanide (NaCN) is a commonly and widely used industrial and laboratory chemical that is highly toxic. Its availability and rapid harmful/lethal effects combine to make cyanide a potential foodborne/waterborne intentional-poisoning hazard. Effective antidotes to cyanide poisoning are currently approved only for intravenous administration. Therefore, an effective cyanide antidote that can be administered intramuscularly in pre-hospital and/or mass-casualty settings is needed. Dimethyl trisulfide (DMTS) is a naturally occurring substance used as a flavour enhancer in foods. DMTS has shown antidotal efficacy in cyanide poisoning and is thought to act as both a sulphur donor and partial methaemoglobin inducer. In this study, an intramuscular injection of DMTS (6.25-200 mg/kg) was given to rats 1 minute after an oral dose of NaCN (98.2 mg/kg; twice the median lethal dose) to test the antidotal efficacy and safety of DMTS treatment. Toxic signs and survival were examined along with behavioural function (up to 30 hour after ingestion) using a previously established operant behavioural model. A large range of DMTS doses (6.25-100 mg/kg) increased survival after oral cyanide poisoning, and the lower DMTS doses (6.25-25 mg/kg) also proved to be behaviourally and physiologically safe. Larger DMTS doses (50-200 mg/kg) produced side effects (ie, inflammation and limping) that were more severe and protracted than those observed at lower DMTS doses. The 25 mg/kg DMTS proved to be the most efficacious (increasing survival from 20% to 75%) and also produced minimal side effects (eg, inflammation) that resolved within 24-72 hour. Thus, DMTS shows promise as an intramuscularly administered cyanide antidote useful for prompt pre-hospital or mass-casualty emergency medical treatment., (Published 2019. This article is a U.S. Government work and is in the public domain in the USA.)

Introduction : Intravenous lipid emulsion (ILE) administration is capable of reversing the acute cardiac and neurological toxicity caused by local anesthetic agents. In recent years, ILE has also been explored as a potential antidote for cardiotoxicity caused by non-anesthetic agents too. Areas covered : The potential mechanisms, safety, and efficacy of this approach are considered. Data were sought from published reports listed in PubMed and EMBASE, and abstracts of meetings of the North American Congress of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. There were reports involving 298 patients where ILE has been administered for severe drug toxicity. Clinical improvement was observed in 57 of 59 patients with local anesthetic toxicity (96.6%); there were 239 patients where toxicity was due to non-anesthetic agents, and ILE apparently improved clinical outcome in 215 (72.1%). Expert opinion : Response rates were similar between ILE treated toxicity caused by lipid soluble and non-lipid soluble drugs. Potential adverse effects of ILE include interference with laboratory assays, acute pancreatitis, and adult respiratory distress syndrome, although the rate of occurrence is difficult to ascertain.

The global use of organophosphorus compounds (OP) for pest control and nerve agents being used in military conflicts and for assassinations renders intoxications by these agents a public health concern. OP-poisoned patients often suffer from dysrhythmias which may ultimately result in death. In this study, human-induced pluripotent stem cells derived cardiomyocytes were exposed to OP compounds in a microelectrode array system (MEA). The MEA system is widely accepted to assess the proarrhythmic properties of (candidate) drugs. The directly acting cholinergic compounds acetylcholine and carbachol and the irreversible acetylcholinesterase inhibitor cyclosarin - a highly toxic nerve agent - were assessed. All three compounds induced a dose-dependent (up to 600 nmol/L) corrected field potential duration (FPDc) prolongation of 9.7 ± 0.6% for carbachol, for 9.7 ± 1.2% acetylcholine and 9.4 ± 0.5% for cyclosarin. Additionally, the electrophysiological alterations of the clinically approved oxime reactivators obidoxime, pralidoxime and the oximes in development HI-6 and MMB-4 were investigated in the absence of OP. Neither of these oximes (up to a concentration of 300 μmol/L) caused dysrhythmia nor beat arrest. The competitive muscarinic receptor antagonist atropine as a cornerstone in the treatment of OP poisoning was also analyzed. Interestingly, atropine caused a drop in the beat rate which might result from a non-receptor action of this substance in the absence of OP. Atropine in combination with the OP nerve agent cyclosarin and the direct cholinergics acetylcholine or carabachol completely reversed the induced FPDc prolongation. However, the oxime HI-6 as potent reactivator of cyclosarin-inhibited AChE was not able to prevent the FPDc prolongation in this model. In conclusion, the current model allows the assessment of FPDc prolongation by the nerve agent cyclosarin, the cholinergic compounds carbachol, acetylcholine and the block of this effect by atropine., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In light of an aging population with increased cardiovascular comorbidity, the use of oral anticoagulation (OAC) is steadily expanding. A variety of pharmacological alternatives to vitamin K antagonists (VKA) have emerged over recent years (direct oral anticoagulants, DOAC, i.e., dabigatran, rivaroxaban, apixaban, and edoxaban) which show a reduced risk for the occurrence of intracerebral hemorrhage (ICH). Yet, in the event of ICH under OAC (OAC-ICH), hematoma characteristics are similarly severe and clinical outcomes likewise substantially limited in both patients with VKA- and DOAC-ICH, which is why optimal acute hemostatic treatment in all OAC-ICH needs to be guaranteed. Currently, International Guidelines for the hemostatic management of patients with OAC-ICH are updated as several relevant large-sized observational studies and recent trials have established treatment approaches for both VKA- and DOAC-ICH. While the management of VKA-ICH is mainly based on the immediate reversal of elevated levels of international normalized ratio using prothrombin complex concentrates, hemostatic management of DOAC-associated ICH is challenging requiring specific antidotes, notably idarucizumab and andexanet alfa. This review will provide an overview of the latest studies and trials on hemostatic reversal agents and timing and summarizes the effects on hemorrhage progression and clinical outcomes in patients with OAC-ICH.

Introduction: Organophosphate (OP) poisoning is an important public health concern in South-Asia especially in the farming population. Treatment of OP poisoning has remained unchanged since decades and case fatality is 10-40% despite best supportive care, anticholinergic agents and oximes. A new antidote is the need of the hour. Lipid emulsion being inexpensive, easily available and effective in management of other lipid soluble toxins may be a novel option. However, safety has not been established and efficacy is limited to animal studies and case reports in humans with OP poisoning., Methods: An open-label pilot study was undertaken to establish the safety of lipid emulsion in OP poisoning. Patients with symptomatic OP poisoning, meeting the inclusion and exclusion criteria were treated with 100 mL of 20% intravenous lipid emulsion (after consent) in addition to standard of care. They were monitored for change in hemodynamic parameters, change in hematology and biochemical parameters at various intervals of time after initiation of therapy. Morbidity, mortality, and occurrence of adverse effects were compared with historical control group., Results: Forty patients with symptomatic OP poisoning were enrolled in the study group. No significant change in hemodynamic parameters (pulse rate, systolic, diastolic blood pressure, and mean arterial pressure) or in hematology and biochemical parameters were seen. No adverse effects were noted. Compared to historical controls, no change in mortality was noted, although there was reduced duration of mechanical ventilation, hospital stay, and early resolution of hypernatremia., Conclusions: This study evaluates the safety of lipid emulsion in OP poisoning. Absence of change in hemodynamic parameters and adverse effects suggests lipid emulsion may be safe for this indication. Large randomized controlled trials are now required to assess clinical efficacy. ClinicalTrials.gov number: NCT03564574.

Context: To compare degree of liver injury and paracetamol metabolite concentrations after treatment with standard of care (20-h) vs. abbreviated (12-h) acetylcysteine regimens used in paracetamol overdose (NACSTOP trial)., Methods: Timed blood samples from a cohort of subjects enrolled in the cluster-controlled NACSTOP trial evaluating a 12-h acetylcysteine regimen (200 mg/kg over 4 h, 50 mg/kg over 8 h) were assayed for paracetamol metabolites as a pilot study, using liquid chromatography/mass spectrometry. Control group subjects received a 20-h course of acetylcysteine (200 mg/kg over 4 h, 100 mg/kg over 16 h). The intervention group received a 12-h acetylcysteine regimen (stopped after at least 12 h of treatment). Positive control groups not in the trial with acute liver injury (ALI) or hepatotoxicity were also studied., Results: One hundred and forty-one blood samples were collected from 40 patients receiving acetylcysteine after paracetamol overdose. Median ALT after 20 h of acetylcysteine was 12 U/L (IQR 8.14) in the abbreviated regimen group, compared to the control group 16 U/L (IQR 11.21) (p = .46). There was no significant difference in median metabolite concentrations on presentation and after 20 h of acetylcysteine between these two groups (p > .05). Presentation median sum CYP-metabolite/total metabolite percentages were 2.5 and 3.0 in the abbreviated and control NACSTOP groups, respectively., Conclusions: An abbreviated 12-h acetylcysteine regimen for paracetamol overdose used in the NACSTOP trial had similar circulating metabolite concentrations compared to a 20-h regimen in selected subjects with low risk of hepatotoxicity. This suggests that further acetylcysteine may not be needed in the abbreviated group at time of cessation.

Essentials In 2016 the SSC proposed definitions for effective hemostasis in management of major bleeding. To validate these definitions, we studied the use in three large anticoagulant-reversal studies. Method agreement analysis and interobserver reliability showed at least acceptable agreement. Recommendations were made, advising use of the definition in hemostatic effectiveness studies. SUMMARY: Introduction In 2016 the Scientific and Standardization Subcommittee (SSC) on Control of Anticoagulation of the International Society on Thrombosis and Haemostasis (ISTH) proposed criteria to evaluate the effectiveness of anticoagulant reversal in major bleeding management. Testing and validation of these criteria are required. Objective To investigate the method agreement, interobserver reliability and applicability of the ISTH proposed definitions for hemostatic effectiveness. Methods Patient data from three anticoagulant-antidote studies were used for hemostatic effectiveness assessment using the ISTH-proposed definitions and clinical opinion. For every patient a case document was produced. For each cohort, four adjudicators were asked to assess the hemostatic effectiveness independently on a case-by-case basis. Agreement between the two methods of hemostatic effectiveness assessment was calculated using Cohen's kappa (κ), with a calculated sample size of at least 73 cases. Results The full dataset consisted of 116 cases, resulting in 464 assessments. Method agreement in outcome was observed in 364 of 464 assessments (78.5%), resulting in κ of 0.634 (95% CI: 0.575-0.694), or "substantial agreement." Interobserver reliability analysis of the proposed definitions computed an overall agreement of 54.2% with κ of 0.312 ("fair agreement"). Discussion Method agreement analysis shows that the conclusions drawn using the ISTH definitions have "substantial agreement" with clinical opinion. Interobserver reliability analysis demonstrated acceptable agreement. In-depth analysis provided minor opportunities for further improvement and correct application of the definition. The definition is recommended to be used in all future studies evaluating hemostatic effectiveness, taking the suggested recommendations into account., (© 2019 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.)

Aims: Because practice-based data on the usage of idarucizumab for urgent dabigatran reversal is unavailable, we evaluated the appropriateness of idarucizumab usage, its haemostatic effectiveness and clinical outcomes., Methods and Results: An observational cohort study was performed including consecutive patients who were treated with idarucizumab between 2016 and 2018. Appropriate usage was assessed with predefined criteria. Post-reversal effectiveness was evaluated according to International Society on Thrombosis and Haemostasis (ISTH) recommendations. Patients were followed for 90 days for occurrence of thromboembolism, (re-)bleeding and death. Idarucizumab was used in 88 patients, of whom 53 (60%) presented with severe bleeding (20 gastrointestinal and 18 intracranial) and 35 (40%) requiring urgent surgical intervention. Use of idarucizumab was judged inappropriate in 25 patients (28%). Effective haemostasis was achieved in 32 of 48 (67%) bleeding patients in whom assessment was possible. Seven of 16 patients with major bleeding who did not achieve effective haemostasis (five intracranial) died, compared with two of 32 patients with effective haemostasis (relative risk 7.0, 95% confidence interval 1.6-30). Four patients (4.2%) developed thromboembolism [2 (2.1%) within 30 days] and four patients (4.2%) re-bleeding, all within 10 days. Seventeen patients (19%) died; 10 (11%) within 5 days., Conclusion: In this practice-based cohort, idarucizumab use was considered inappropriate in 28% of patients. Effective haemostasis was achieved in two-third of bleeding patients and was associated with lower mortality risk. Clinical outcomes were similar to those observed in the RE-VERSE AD trial, comprising re-bleeds and thromboembolism, and a high-mortality rate., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Context: Poison centers (PCs) frequently manage patients with antimuscarinic delirium. However, controversy surrounds the antidotal use of physostigmine for its treatment. The aim of this study was to prospectively investigate physostigmine versus non-antidote therapy for the management of antimuscarinic delirium in a single regional PC., Methods: This was a prospective observational analysis of patients diagnosed with antimuscarinic delirium and treated in consultation with a regional PC. Certified Specialists in Poison Information (CSPIs) use a clinical guideline to recommend the use of physostigmine. Using a previously derived altered mental status score, we quantified the rate of delirium improvement with physostigmine compared to non-antidote therapy two hours after initial patient identification. We also recorded adverse events (defined a priori as bradycardia, vomiting, seizures) and resource utilization (intubation and physical restraint)., Results: We identified 245 patients and included 154 in the analysis. The most common exposure classes were antihistamines (68%), analgesics (19%), and antipsychotics (19%). CSPIs recommended physostigmine in 81% (125) of cases and the treatment team administered it in 37% (57) of these. We observed delirium control in 79% of patients who received physostigmine versus 36% of those who did not. The odds of delirium control were six times greater for patients receiving physostigmine than for patients treated with non-antidote therapy (OR 6.6). Adverse events were rare and did not differ significantly between the groups. Physostigmine was not associated with changes in the incidence of intubation or restraint., Conclusions: This study provides further evidence of both the safety and efficacy of physostigmine in the treatment of antimuscarinic delirium.

Background: Intravenous thrombolysis (IVT) is contraindicated in patients with acute ischemic stroke (AIS) using oral anticoagulants. A specific human monoclonal antibody was introduced to reverse immediately the anticoagulation effect of the direct inhibitor of thrombin, dabigatran. Until now, mostly individual cases presenting with successful IVT after a reversal of dabigatran anticoagulation in patients with AIS were published. Thus, we aimed to report real-world data from clinical practice., Methods: Patients with AIS on dabigatran treated with IVT after antidote reversal were enrolled in the retrospective nationwide study. Neurological deficit was scored using the National Institutes of Health Stroke Scale (NIHSS) and 90-day clinical outcome using modified Rankin scale (mRS) with a score 0-2 for a good outcome. Intracerebral hemorrhage (ICH) was defined as a presence of any sign of bleeding on control imaging after IVT, and symptomatic intracerebral hemorrhage (SICH) was assessed according to the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) criteria., Results: In total, 13 patients (7 men, mean age 70.0 ± 9.1 years) with a median NIHSS admission score of 7 points were analyzed. Of these patients, 61.5% used 2 × 150 mg of dabigatran daily. Antidote was administrated 427 ± 235 minutes after the last intake of dabigatran, with a mean activated prothrombin time of 38.1 ± 27.8 seconds and a mean thrombin time of 72.2 ± 56.1 seconds. Of the 13 patients, 2 had ICH and 1 had SICH, and no other bleeding complications were observed after IVT. Of the total number of patients, 76.9% had a good 3-month clinical outcome and 3 patients (23.1%) died. Recurrent ischemic stroke occurred in 2 patients (15.4%)., Conclusion: The data presented in the study support the safety and efficacy of IVT after the reversal of the anticoagulation effect of dabigatran with antidote in a real-world clinical practice., (Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Objectives: With a steadily growing number of patients with non-valvular atrial fibrillation, anticoagulation use increases. Anticoagulation therapy is associated with increased risk of serious bleeding and an increased complexity in management of patients in need for urgent surgery. We wanted to assess the magnitude of this challenge as well as review current and potential future clinical management strategies., Design: A review of the literature on the magnitude of patients using antigoaculants in potential need for acute restoration of hemostasis was conducted, as well as current status of reversal agents for non-vitamin K antagonist oral anticoagulants (NOACs). Additionally, a case illustration of its use is presented., Results: Two main groups of patients may need acute restoration of hemostasis, those in need of acute surgery or acute invasive procedures, ∼ 2% of patients annually, and those with serious and critical hemorrhage, ∼1.5% annually. One specific reversal agent is available on the market (idarucizumab) and two (andexanet alfa, ciraparantag) are in clinical development. Idarucizumab is a specific antidote for the thrombin inhibitor dabigatran while andexanet alfa is factor Xa inhibitor class-specific currently in late-stage development. Ciraparantag is a universal reversal agent in early-phase development. These agents can facilitate effective management of bleeding or bleeding risk, as illustrated in a patient on dabigatran in urgent need for a pacemaker., Conclusions: Amongst patients using anticoagulants, around 3.5%, could be in need of immediate restoration of hemostasis annually. The availability and use of specific reversal agents for NOACs could be crucial for the clinical outcomes.

Background: Anaphylactoid reactions to intravenous (IV) N-acetylcysteine (NAC) are well-recognized adverse events during treatment for acetaminophen (APAP) poisoning. Uncertainty exists regarding their incidence, severity, risk factors, and management. We sought to determine the incidence, risk factors, and treatment of anaphylactoid reactions to IV NAC in a large, national cohort of patients admitted to hospital for acetaminophen overdose., Methods: This retrospective medical record review included all patients initiated on the 21-h IV NAC protocol for acetaminophen poisoning in 34 Canadian hospitals between February 1980 and November 2005. The primary outcome was any anaphylactoid reaction, defined as cutaneous (urticaria, pruritus, angioedema) or systemic (hypotension, respiratory symptoms). We examined the incidence, severity and timing of these reactions, and their association with patient and overdose characteristics using multivariable analysis., Results: An anaphylactoid reaction was documented in 528 (8.2%) of 6455 treatment courses, of which 398 (75.4%) were cutaneous. Five hundred four (95.4%) reactions occurred during the first 5 h. Of 403 patients administered any medication for these reactions, 371 (92%) received an antihistamine. Being female (adjusted OR 1.24 [95%CI 1.08, 1.42]) and having taken a single, acute overdose (1.24 [95%CI 1.10, 1.39]) were each associated with more severe reactions, whereas higher serum APAP concentrations were associated with fewer reactions (0.79 [95%CI 0.68, 0.92])., Conclusion: Anaphylactoid reactions to the 21-h IV NAC protocol were uncommon and involved primarily cutaneous symptoms. While the protective effects of higher APAP concentrations are of interest in understanding the pathophysiology, none of the associations identified are strong enough to substantially alter the threshold for NAC initiation.

The non-vitamin K antagonist oral anticoagulants (NOACs) include dabigatran, which inhibits thrombin, and apixaban, betrixaban, edoxaban, and rivaroxaban, which inhibit coagulation factor Xa. Although clinical studies of NOACs were conducted without antidotes, patient outcomes with major bleeding when receiving NOACs were no worse than those in patients treated with a vitamin K antagonist. Nonetheless, in patients with life-threatening bleeding or requiring urgent surgery, the capacity for rapid NOAC reversal is likely to increase patient safety. Three NOAC reversal agents are in various stages of development: idarucizumab, a specific reversal agent for dabigatran; andexanet alfa, which reverses factor Xa inhibitors; and ciraparantag, which is purported to reverse all NOACs. Idarucizumab is licensed in many countries, andexanet is under consideration by regulatory agencies, and ciraparantag is undergoing phase III evaluation. In the absence of licensed reversal agents for the oral factor Xa inhibitors, prothrombin complex concentrates are often used in patients taking these agents who present with life-threatening bleeding. In this Review, we summarize the approved indications for the NOACs, outline how to measure their anticoagulant effects, describe the mechanism of action of the reversal strategies, assess the preclinical and clinical data supporting their use, provide guidance on potential indications for reversal, and offer a management approach for patients treated with NOACs who present with serious bleeding or require urgent surgery.

Context: Hydroxocobalamin is an effective cyanide antidote. While erythema, hypertension, and chromaturia are recognized side effects, methemoglobinemia has not been reported. Methemoglobin levels are most accurately measured by co-oximetry. We describe an extensively burned patient who developed methemoglobinemia within an hour of hydroxocobalamin administration., Case Details: A 47-year old man without genetic deficiencies or abnormal hemoglobin variants presented with 61% body surface area thermal burns and grade 1 inhalation injury sustained during a tugboat engine explosion. On admission, lactate was 9.24 mmol/L, methemoglobin 1%, and carboxyhemoglobin 0.2% by blood gas analysis with co-oximetry. Despite large-volume resuscitation, lactate remained elevated (7-8 mmol/L). Intravenous hydroxocobalamin (5 g) was administered at postburn hour 19 for possible cyanide toxicity. Immediately thereafter, he became hypertensive with reflex bradycardia. Lactate decreased to 5.51 mmol/L, methemoglobin rose to 4.10%, and oxygen saturation by pulse oximetry decreased to 74-80% (despite arterial oxygen saturation of 95% by cooximetry). Methemoglobin concentration peaked at 13.40% at postburn hour 33. Methylene blue was not administered., Conclusions: Methemoglobinemia in our patient was temporally associated with hydroxocobalamin administration.

Background: The purpose of this study was to estimate the frequency and describe the adverse drug reactions (ADRs) associated with the classic treatment of ocular toxoplasmosis (OT), namely sulfadiazine, pyrimethamine, corticosteroids and folinic acid., Methods: We performed a descriptive study of a prospective cohort of patients with OT treated with the classic therapy. Data were collected during medical consultations and treatment., Results: Of the 147 patients studied, 85% developed one or more ADR. Women presented more ADRs than men (95% vs 77%). Of the total reactions (n=394), 82% were mild, but we found one life-threatening event (Stevens-Johnson syndrome). The most frequent types (71%) of ADRs were gastrointestinal, skin and neurological or psychiatric. The majority of ADRs (90.3%) occurred before the second week of treatment. A third of the patients were treated for the ADR and 10% dropped out of OT treatment. Most (70%) of the ADRs were characterized as being probably caused by the drugs and may be associated with prednisone, sulfadiazine and sulfadiazine/prednisone. Six percent of ADRs were not previously described, such as taste alteration, constipation/bloating, dyspnoea, sweating and somnolence., Conclusions: Our results suggest a high rate of ADRs to OT classic treatment, which requires careful follow-up in order to identify and treat ADRs early.

Competing Interests: Competing interests: None declared.