Pharmacological management of anticholinergic delirium - theory, evidence and practice

Seizures due to pyridoxine deficiency in Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized not only by its hallmark motor symptoms but also by a myriad of non-motor manifestations, including cognitive decline, autonomic manifestations, and gastrointestinal disturbances. Amidst these, a lesser-known but critical aspect is the increased risk of functional deficiency of pyridoxine (vitamin B6) in patients with PD, which is linked to an increased risk of seizures. This review investigates the intersection of PD, new-onset seizures, and pyridoxine deficiency, aiming to elucidate the significance of these associations and their contributions to the neurologic burden in PD. Case reports documenting the occurrence of seizures in patients with PD, particularly in the context of high-dose dopaminergic therapy and the subsequent revelation of pyridoxine deficiency were included. These cases, which often featured extensive workups revealing unremarkable findings aside from pyridoxine deficiency, underscore the multifaceted nature of PD and its treatment-related complications. The findings in these case reports suggest that dietary insufficiencies, gastrointestinal dysfunctions, and drug-nutrient interactions may eventually precipitate pyridoxine deficiency, which in turn may lead to seizures by disrupting GABAergic neurotransmission. This sheds the light on the need for increased clinical awareness and routine monitoring of pyridoxine levels in patients with PD, especially those undergoing significant therapeutic adjustments or exhibiting comorbidities that might interfere with their dietary intake such as gastrointestinal manifestations or depression. Such proactive measures could potentially mitigate the impact of this complication in patients with PD, ultimately enhancing patient care and quality of life.

An Evidence-Based Update on Anticholinergic Use for Drug-Induced Movement Disorders

Drug-induced movement disorders (DIMDs) are associated with use of dopamine receptor blocking agents (DRBAs), including antipsychotics. The most common forms are drug-induced parkinsonism (DIP), dystonia, akathisia, and tardive dyskinesia (TD). Although rare, neuroleptic malignant syndrome (NMS) is a potentially life-threatening consequence of DRBA exposure. Recommendations for anticholinergic use in patients with DIMDs were developed on the basis of a roundtable discussion with healthcare professionals with extensive expertise in DIMD management, along with a comprehensive literature review. The roundtable agreed that "extrapyramidal symptoms" is a non-specific term that encompasses a range of abnormal movements. As such, it contributes to a misconception that all DIMDs can be treated in the same way, potentially leading to the misuse and overprescribing of anticholinergics. DIMDs are neurobiologically and clinically distinct, with different treatment paradigms and varying levels of evidence for anticholinergic use. Whereas evidence indicates anticholinergics can be effective for DIP and dystonia, they are not recommended for TD, akathisia, or NMS; nor are they supported for preventing DIMDs except in individuals at high risk for acute dystonia. Anticholinergics may induce serious peripheral adverse effects (e.g., urinary retention) and central effects (e.g., impaired cognition), all of which can be highly concerning especially in older adults. Appropriate use of anticholinergics therefore requires careful consideration of the evidence for efficacy (e.g., supportive for DIP but not TD) and the risks for serious adverse events. If used, anticholinergic medications should be prescribed at the lowest effective dose and for limited periods of time. When discontinued, they should be tapered gradually.

Anticholinergic Toxidrome due to Thorn Apple Seed Ingestion in an Elderly Couple

Introduction

Sudden onset of reduced consciousness, psychomotor agitation and mydriasis are all indicative of an anticholinergic toxidrome. It is important to note that numerous drugs, as well as certain herbs and plants, possess anticholinergic properties.

Case description

An 84-year-old female patient had sudden nocturnal onset of uncoordinated hand movements and altered mental status. Shortly after, the patient's 83-year-old husband developed symptoms of dysarthria, gait ataxia, vertigo, and delirium.

Conclusion

Anticholinergic syndrome consists of a combination of central and peripheral anticholinergic symptoms. Physostigmine given intravenously resulted in rapid reversal of symptoms. Thorn apple seeds had been accidentally ingested and were identified as the cause.

LEARNING POINTS

The clinical presentation of an anticholinergic toxidrome includes both central and peripheral symptoms such as altered consciousness, mydriasis, dry mucous membranes and skin, and tachycardia.Prompt recognition of anticholinergic toxidrome and the administration of physostigmine can lead to rapid reversal of symptoms and improved patient outcomes.Treatment with physostigmine is indicated when a patient with an agitated delirium does not respond adequately to titrated benzodiazepines.

Predictors of postoperative delirium in paediatric patients undergoing surgery under general anaesthesia at Amhara Regional State Tertiary Hospitals: a multicenter prospective study

Introduction

Postoperative delirium in paediatric patients is a recognised issue. Nevertheless, in low- and middle-income nations, researchers have had luck in determining its extent and predictors. Identifying predictors of postoperative delirium in paediatric patients having general anaesthesia at Tertiary Hospitals in Ethiopia was the aim of this study.

Methods

A multicenter, prospective follow up study was conducted from April 15 to June 15, 2023 at the study settings. During the study period a total of 424 paediatric surgical patients treated under general anaesthesia in all study locations, ranging in age from birth to sixteen were candidates for this study. Charts and direct observation of patient's with assessment tool [Cornell Assessment of Pediatric Delirium (CAPD)] were used from each available patient. Binary logistic regression analysis was performed to determine predictors of postoperative delirium in paediatric patients undergoing surgery under general anaesthesia.

Results

Postoperative delirium occurred in 160 of the 404 paediatric patients who underwent surgery under general anaesthesia. Ophthalmic surgery, corticosteroid use, anticholinergic use, severe postoperative pain, and preoperative anxiety were found to be predictors of postoperative delirium; whereas, sedative medication premedication and paracetamol used for analgesia were found to be protective against postoperative delirium.

Inference and recommendation

The postoperative delirium in paediatric patients undergoing surgery under general anaesthesia was higher compared to developed countries. Ophthalmic surgery, corticosteroids, anticholinergic medications, postoperative pain, and preoperative anxiety were found to be predictors. The impact of postoperative delirium might be lessened by concentrating on its screening and factor control.

Rivastigmine for the management of anticholinergic delirium

INTRODUCTION

Anticholinergic agents are commonly taken in overdose, often causing delirium. The spectrum of anticholinergic delirium ranges from mild agitation to severe behavioural disturbance. Physostigmine is an effective treatment for anticholinergic delirium, but its availability is limited. As rivastigmine is readily available, it has been used to manage anticholinergic delirium; however, there is limited research investigating its use.

METHOD

This was a retrospective review of patients with anticholinergic delirium treated in two toxicology units with rivastigmine (oral capsule or transdermal patch) from January 2019 to June 2023. The primary outcome was the use of further parenteral treatment (sedation or physostigmine) for delirium post rivastigmine administration.

RESULTS

Fifty patients were administered rivastigmine for the management of anticholinergic delirium. The median age was 36 years (interquartile range: 25-49 years) and 27 (54 per cent) were females. Features consistent with anticholinergic toxicity included tachycardia in 44 (88 per cent) and urinary retention requiring catheterisation in 40 (80 per cent). Forty-three patients (86 per cent) were treated with physostigmine before rivastigmine administration. Twenty-two were managed with transdermal rivastigmine (most commonly 9.5 mg/24 hour patch), and 28 with oral rivastigmine 6 mg. Further parenteral sedation and/or physostigmine treatment were required more often in patients given transdermal than oral rivastigmine [16/22 (73 per cent) versus 9/28 (32 per cent), P = 0.010)]. No patients had bradycardia or gastrointestinal symptoms following rivastigmine administration. One patient with a history of epilepsy had a seizure, 1.5 hours post physostigmine administration and 7 hours post transdermal rivastigmine.

DISCUSSION

Rivastigmine has been increasingly used for the management of patients with anticholinergic delirium, due to the lack of availability of physostigmine. In this case series, rivastigmine transdermal patch appeared to be less effective than oral rivastigmine capsules, likely due to its slow onset of action and/or insufficient dose.

CONCLUSION

Rivastigmine can be used to treat anticholinergic delirium. In our case series oral rivastigmine appeared more effective than transdermal rivastigmine.

Safety of Physostigmine for Pediatric Antimuscarinic Poisoning

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.

Decoding the Neurological Sequelae of General Anesthesia: A Review

General anesthesia is an integral part of modern surgical practice, but it is associated with a number of complications, including neurological ones. This article provides a thorough analysis of these complications, taking into account the most common ones like drug complications, through delirium, postoperative cognitive impairment (POCD), to the rarest ones like perioperative stroke (POS), spinal cord ischemia (SCI), and postoperative visual loss (POVL). Its main goal is to familiarize healthcare professionals, especially those involved in anesthesiology, with the intricacies of neurological complications. Given their specificity and frequency of occurrence, it is well known that the diagnosis and management of these complications can sometimes cause problems for physicians without advanced neurological knowledge. Also, in addition to complex diagnostics, the pathomechanism of non-pharmacological complications is often not fully understood due to their multifactoriality and sometimes paucity of research. For this reason, an increasing amount of work is being done in the medical community to better understand this group of conditions, enabling faster diagnosis and more effective treatment, as well as perioperative prevention. This paper aims to increase awareness and vigilance among physicians across the spectrum of surgical patient care, from premedication to postoperative follow-up. Drawing on the authors' experience and the extensive medical literature, this paper includes 39 selected articles from 1994 to 2023, seeking the latest insights in the constantly evolving field of neurology and anesthesiology. This article aims to review the neurological complications of general anesthesia.

[Pharmacological Management of Postoperative Delirium]

Postoperative delirium (POD) is a complex disorder with significant implications for health and well-being. Over the last few years, there has been a significant increase in awareness of the pathophysiological processes, the different clinical forms and the prevention of POD. It is known that POD develops when anaesthetic- and surgery-related precipitating factors coincide with the patient's predisposing vulnerability. Consequently, assessing the preoperative physical, cognitive, psychological, social and resilience capabilities of patients scheduled for surgery is critical to assessing overall risk and determining optimal preoperative, intraoperative and postoperative management, particularly as pharmacological treatment options remain limited. For treatment, non-pharmacological measures remain in the foreground, pharmacological therapy is only used for severe symptoms, and should be symptom-oriented and low-dosed. There is no drug that is suitable for delirium treatment alone.

Antidotes in Clinical Toxicology-Critical Review

Poisoning and overdose are very important aspects in medicine and toxicology. Chemical weapons pose a threat to civilians, and emergency medicine principles must be followed when dealing with patients who have been poisoned or overdosed. Antidotes have been used for centuries and modern research has led to the development of new antidotes that can accelerate the elimination of toxins from the body. Although some antidotes have become less relevant due to modern intensive care techniques, they can still save lives or reduce the severity of toxicity. The availability of antidotes is crucial, especially in developing countries where intensive care facilities may be limited. This article aims to provide information on specific antidotes, their recommended uses, and potential risks and new uses. In the case of poisoning, supportive therapies are most often used; however, in many cases, the administration of an appropriate antidote saves the patient's life. In this review, we reviewed the literature on selected antidotes used in the treatment of poisonings. We also characterised the antidotes (bio)chemically. We described the cases in which they are used together with the dosage recommendations. We also analysed the mechanisms of action. In addition, we described alternative methods of using a given substance as a drug, an example of which is N-acetylcysteine, which can be used in the treatment of COVID-19. This article was written as part of the implementation of the project of the Polish Ministry of Education and Science, "Toxicovigilance, poisoning prevention, and first aid in poisoning with xenobiotics of current clinical importance in Poland", grant number SKN/SP/570184/2023.

[Central anticholinergic, neuroleptic malignant and serotonin syndromes]

Impaired consciousness is a frequent phenomenon after general anesthesia. In addition to the classical causes (e.g., overhang of sedatives), an impairment of consciousness can also be an adverse side effect of drugs. Many drugs used in anesthesia can trigger these symptoms. Alkaloids, such as atropine can trigger a central anticholinergic syndrome, opioids can promote the occurrence of serotonin syndrome and the administration of a neuroleptic can lead to neuroleptic malignant syndrome. These three syndromes are difficult to diagnose due to the individually very heterogeneous symptoms. Mutual symptoms, such as impaired consciousness, tachycardia, hypertension and fever further complicate the differentiation between the syndromes; however, more individual symptoms, such as sweating, muscle tension or bowl sounds can be helpful in distinguishing these syndromes. The time from the trigger event can also help to differentiate the syndromes. The central anticholinergic syndrome is the fastest to appear, usually taking just a few of hours from trigger to clinical signs, serotonin syndrome takes several hours up to 1 day to show and neuroleptic malignant syndrome usually takes days. The clinical symptoms can range from mild to life-threatening. Generally, mild cases are treated with discontinuation of the trigger and extended observation. More severe cases can require specific antidotes. The specific treatment recommended for central anticholinergic syndrome is physostigmine with an initial dose of 2 mg (0.04 mg/kg body weight, BW) administered over 5 min. For serotonin syndrome an initial dose of 12 mg cyproheptadine followed by 2 mg every 2 h is recommended (maximum 32 mg/day or 0.5 mg/kgBW day-1) but this medication is only available in Germany as an oral formulation. For neuroleptic malignant syndrome 25-120 mg dantrolene (1-2.5 mg/kgBW maximum 10 mg/kgBW day-1) is the recommended treatment.

Diphenhydramine-Induced Antimuscarinic Delirium Treated with Physostigmine and Transdermal Rivastigmine

INTRODUCTION

Recurrent physostigmine shortages present a challenge to healthcare providers treating antimuscarinic delirium. Other centrally acting acetylcholinesterase inhibitors such as rivastigmine may represent a therapeutic alternative or adjunct during physostigmine shortage; however, previous reports of use have not documented serum antimuscarinic toxin concentrations, limiting evaluation of effectiveness. Combination therapy with physostigmine and rivastigmine has not been described. In this report, the authors present a case of diphenhydramine-induced antimuscarinic delirium with elevated diphenhydramine serum concentrations treated with physostigmine and transdermal rivastigmine without observed adverse effect.

CASE REPORT

A 48-year-old female presented to an emergency department after ingesting 3.75 g (41.2 mg/kg) of diphenhydramine. She had antimuscarinic delirium with a presenting serum diphenhydramine concentration of 1500 ng/mL (therapeutic range, 25-112 ng/mL) and required two doses of physostigmine to avert intubation prior to intensive care unit (ICU) admission. At hospital hour 22, in the ICU, antimuscarinic delirium persisted but no further physostigmine was available due to hospital shortage. Therefore, a 9.5-mg transdermal rivastigmine patch was applied. By hospital hour 24, her delirium had resolved. A serum diphenhydramine concentration at hospital hour 25 was elevated at 760 ng/mL. Transdermal rivastigmine was discontinued at hospital hour 48 without recurrent delirium. Despite persistent normal mental status after rivastigmine discontinuation, the patient had a dry mouth, difficulty urinating, and mydriasis until hospital day 5. She never developed muscarinic toxicity.

DISCUSSION

Transdermal rivastigmine may be a useful treatment alternative or adjunct during physostigmine shortage for antimuscarinic delirium and has a long duration of action without aspiration risk. Muscarinic toxicity was not observed.

Shortages of agents used to treat antimuscarinic delirium

INTRODUCTION

Antimuscarinic delirium (AD), a potentially life-threatening condition frequently encountered by emergency physicians, results from poisoning with antimuscarinic agents. Treatment with physostigmine and benzodiazepines is the mainstay of pharmacotherapy, and use of dexmedetomidine and non-physostigmine centrally-acting acetylcholinesterase inhibitors (cAChEi) such as rivastigmine has also been described. Unfortunately, these medications are subject to drug shortages which negatively impact the ability to provide appropriate pharmacologic treatment of patients with AD.

METHODS

Drug shortage data were retrieved from the University of Utah Drug Information Service (UUDIS) database from January 2001 through December 2021. Shortages of first-line agents used to treat AD (physostigmine and parenteral benzodiazepines) and second-line agents (dexmedetomidine and non-physostigmine cAChEi) were examined. Drug class, formulation, route of administration, reason for shortage, shortage duration, generic status, and whether the drug was a single-source product (made by only one manufacturer) were extracted. Shortage overlap and median shortage durations were calculated.

RESULTS

Twenty-six shortages impacting drugs used to treat AD were reported to UUDIS from January 1, 2001 to December 31, 2021. Median shortage duration for all medication classes was 6.0 months. Four shortages were unresolved at the end of the study period. The single medication most often on shortage was dexmedetomidine, however benzodiazepines were the most common medication class on shortage. Twenty-five shortages involved parenteral formulations, and one shortage involved the transdermal patch formulation of rivastigmine. The majority (88.5%) of shortages involved generic medications, and 50% of products on shortage were single-source. The most common reported reason for shortage was a manufacturing issue (27%). Shortages were often prolonged and, in 92% of cases, overlapped temporally with other shortages. Shortage frequency and duration increased during the second half of the study period.

CONCLUSION

Shortages of agents used in the treatment of AD were common during the study period and affected all agent classes. Shortages were often prolonged and multiple shortages were ongoing at study period end. Multiple concurrent shortages involving different agents occurred, which could hamper substitution as a means of mitigating shortage. Healthcare stakeholders must develop innovative patient- and institution-specific solutions in times of shortage and work to build resilience into the medical product supply chain to minimize future shortages of drugs used for treatment of AD.

Delirium secondary to anticholinergics

We present a case of a young man who developed sudden deterioration in his physical and mental state whilst being treated as an inpatient for substance-induced psychosis. This deterioration was manifested by sudden disorientation, change in behaviour and visual hallucinations. It was only after excluding other potential causes that this presentation was attributed to the regular administration of procyclidine that was being used to counteract the extrapyramidal side effects from antipsychotics. The patient showed a dramatic improvement on stopping procyclidine. This case highlights the importance of awareness of rare adverse drug reactions and the resultant distressing effect for the patient himself.

[Central anticholinergic, neuroleptic malignant and serotonin syndromes : Important differential diagnoses in postoperative impairment of consciousness]

Impaired consciousness is a frequent phenomenon after general anesthesia. In addition to the classical causes (e.g., overhang of sedatives), an impairment of consciousness can also be an adverse side effect of drugs. Many drugs used in anesthesia can trigger these symptoms. Alkaloids, such as atropine can trigger a central anticholinergic syndrome, opioids can promote the occurrence of serotonin syndrome and the administration of a neuroleptic can lead to neuroleptic malignant syndrome. These three syndromes are difficult to diagnose due to the individually very heterogeneous symptoms. Mutual symptoms, such as impaired consciousness, tachycardia, hypertension and fever further complicate the differentiation between the syndromes; however, more individual symptoms, such as sweating, muscle tension or bowl sounds can be helpful in distinguishing these syndromes. The time from the trigger event can also help to differentiate the syndromes. The central anticholinergic syndrome is the fastest to appear, usually taking just a few of hours from trigger to clinical signs, serotonin syndrome takes several hours up to 1 day to show and neuroleptic malignant syndrome usually takes days. The clinical symptoms can range from mild to life-threatening. Generally, mild cases are treated with discontinuation of the trigger and extended observation. More severe cases can require specific antidotes. The specific treatment recommended for central anticholinergic syndrome is physostigmine with an initial dose of 2 mg (0.04 mg/kg body weight, BW) administered over 5 min. For serotonin syndrome an initial dose of 12 mg cyproheptadine followed by 2 mg every 2 h is recommended (maximum 32 mg/day or 0.5 mg/kgBW day^-1) but this medication is only available in Germany as an oral formulation. For neuroleptic malignant syndrome 25-120 mg dantrolene (1-2.5 mg/kgBW maximum 10 mg/kgBW day^-1) is the recommended treatment.

The Twilight Zone: Oxybutynin Overuse Exacerbating Delirium

Anticholinergic medications, such as oxybutynin, are first-line pharmacologic therapies in overactive bladder. However, the cognitive adverse effect profiles of frequently used anticholinergic medications are extensive and limit their use in older patients. Additionally, many older patients continue on anticholinergic therapy if adverse effects are not self-reported by the patient or detected by the provider.Here, we present a case of a 73-year-old male with a history of major neurocognitive disorder, in which unreported oxybutynin overuse led to repeated delirious states, erratic driving, and subsequent psychiatric hospitalizations. During his hospitalizations, he displayed progressively more linear thought processes and improved insight without clear etiology. After a more thorough history of his medication use was obtained, he disclosed that he would often take additional doses of oxybutynin to prevent incontinence during car rides and had done so prior to recent hospitalizations.Our example highlights the importance of thorough history taking, medication review, reducing polypharmacy, careful patient education about medications with psychiatric adverse effects, and, importantly, the avoidance of anticholinergic medication prescription in older patients.

Prevalence of Emergence Delirium and Associated Factors among Older Patients Who Underwent Elective Surgery: A Multicenter Observational Study

Background

Emergence delirium is a common and serious postoperative complication in older surgical patients. It occurs at any time in the perioperative period, during or immediately following emergence from general anesthesia. Unfortunately, it is highly associated with postoperative complications such as a decrease in functional capacity, prolonged hospital stay, an increase in health care costs, and morbidity and mortality. The goal of this study was to determine the prevalence of emergence delirium and associated factors among older patients who underwent elective surgery in the teaching hospitals of Ethiopia at the postanesthesia care unit in 2021.

Methods

A multicenter prospective observational study was conducted at the postanesthetic care unit in the four teaching hospitals of Ethiopia. Older surgical patients admitted to the postanesthesia care unit who underwent elective surgery in the four teaching hospitals of Ethiopia were selected by using simple random sampling. Pretested structured questionnaire was used to collect data. Data were entered into EpiData (version 4.6) and exported to the SPSS (version 25.0). Binary logistic regression was used to identify factors independently associated with the emergence delirium.

Results

Out of 384 older patients included in the study, the prevalence of emergence delirium was 27.6%. Preoperative low hemoglobin levels (AOR: 2.0, 95% CI; 1.77–3.46), opioid (AOR: 8.0, 95% CI; 3.22–27.8), anticholinergic premedications (AOR: 8.5, 95% CI; 6.85–17.35), and postoperative pain (AOR: 3.10, 95 CI; 2.07–9.84) at PACU were independently associated with emergence delirium.

Conclusion

The prevalence of emergence delirium was high among older patients who underwent elective surgery. Opioid and anticholinergic premedication, low preoperative hemoglobin, and the presence of postoperative pain were independently associated with the emergence delirium. Adequate preoperative optimization and postoperative analgesia may reduce the prevalence of emergence delirium.

Significance of temperature in antimuscarinic toxicity: a case-control study

INTRODUCTION

Antimuscarinic toxicity can result in temperature dysregulation, but the clinical significance of this is unclear. The objective of this study was to compare peak temperatures between antimuscarinic patients with and without severe clinical outcomes.

METHODS

This was a case-control analysis at two large, urban, academic medical centers from January 1, 2016, through December 31, 2021. We compared peak temperature (T_max) amongst antimuscarinic patients who experienced severe outcomes with those who did not. Severe outcome was defined as seizure, ventricular dysrhythmia, hypotension, or intubation.

RESULTS

Fifty-six patients met inclusion criteria of which 23 developed severe outcomes: 16 seizures, 9 cases with hypotension, 5 intubations, and 2 ventricular dysrhythmias. Tmax amongst all patients ranged from 36.4-39.2 °C. There were no fatalities. There was no difference in Tmax in the emergency department or throughout hospitalization between groups, and Tmax was not predictive for the development of severe outcomes.

DISCUSSION

Maximum temperatures did not differ between patients with and without severe outcomes in the setting of antimuscarinic toxicity, and temperature was poorly predictive of outcomes. Our findings suggest that mild temperature dysregulation in antimuscarinic toxicity is not a key prognostic indicator for severe outcome. Further study is needed to assess implication of severe hyperthermia.

Effects of non-pharmacological interventions for preventing delirium in general ward inpatients: A systematic review & meta-analysis of randomized controlled trials

The purpose of this study was to identify the types and contents of non-pharmacological delirium prevention interventions applied to inpatients in general wards, and to verified the effectiveness of the interventions on the incidence of delirium. We performed an extensive search of bibliographic databases and registries (CENTRAL, MEDLINE, EMBASE, CINAHL, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform, PubMed and Google Scholar, and Korean DB such as RISS, DBpia, KISS, NDSL and KCI) using terms to identify delirium, prevention, and non-pharmacological. We searched all databases from their inception to January 2021 and imposed restriction on language of publication in English and Korean. We included studies if they were conducted as all types of randomized controlled trials (RCT), involving adult patients aged 19 years or more who were admitted to a general ward. We included trials comparing non-pharmacological intervention versus usual care. The entire process of data selection and extraction, assessment of risk of bias with ROB2.O was independently performed by three researchers. The estimated effect size was an odds ratio (OR) and 95% confidence interval. The fixed effects model and general inverse variance estimation method were adopted. The type of non-pharmacological delirium prevention interventions for inpatients in general ward was mainly multi-component intervention to correct delirium risk factors. The content and intensity of non-pharmacological interventions varied greatly depending on the characteristics of the patient and the clinical situation. As a result of the meta-analysis, non-pharmacological multi-component intervention was effective in reducing the incidence of delirium, and it was confirmed that it was effective in reducing the incidence of delirium in both the internal and surgical wards. It was confirmed by quantitative evidence that non-pharmacological interventions, especially multi-component interventions, were effective in preventing delirium in general ward inpatients.

A sabbath in the emergency room or a case of anticholinergic toxicity?

We report the case of a 32-year-old Italian man admitted to our emergency room for visual disturbances with blurred vision, anisocoria and temporal headache suddenly occurred in absence of other neurological symptoms. A diagnosis of Datura stramoniuminduced anticholinergic toxicity was done. With our work, we want to highlight the importance of a meticulous clinical examination, including papillary diameter and reflexes, combined with a detailed history of the patient in the emergency room. Anticholinergic toxicity is a medical emergency. The diagnosis is always clinical, and it can represent a challenge for the emergency clinicians because it can mimic several neurological diseases, including acute stroke and seizures, but early diagnosis is crucial to avoid severe complications and management errors.

Delirium in Older Adults: What a Surgeon Needs to Know

Delirium remains a challenging clinical problem in hospitalized older adults, especially for postoperative patients. This complication, with a high risk of postoperative mortality and an increased length of stay, frequently occurs in older adult patients. This brief narrative paper aims to review the recent literature regarding delirium and its most recent update. We also offer physicians a brief and essential clinical practice guide to managing this acute and common disease.

Incidence of Drug-Induced Delirium During Treatment With Antidepressants or Antipsychotics: A Drug Surveillance Report of German-Speaking Countries Between 1993 and 2016

OBJECTIVES

Successful treatment of delirium depends on the detection of the reversible contributors. Drugs with delirogenic properties are the most prevalent reversible cause of delirium.

METHODS

This observational study is based on data from Arzneimittelsicherheit in der Psychiatrie, a multicenter drug surveillance program in German-speaking countries recording severe adverse drug reactions (ADRs) in psychiatric inpatients. The present study analyzes drug-induced delirium (DID) during treatment with antidepressants and antipsychotics.

RESULTS

A total of 436 565 psychiatric inpatients were treated with antidepressants and/or antipsychotics during the observation period from 1993 to 2016 in the participating 110 hospitals. Overall, 254 cases (0.06% of all patients treated with antidepressants and/or antipsychotics) of DID were detected. Implicated either in combination or alone (multiple drugs were implicated in 70.1% of DID), clomipramine (0.24%), amitriptyline (0.21%), and clozapine (0.18%) showed the highest incidence rates of DID. When implicated alone (98 cases overall), clozapine (0.11%) followed by amitriptyline (0.05%) were most likely causally associated with the occurrence of DID. Drugs with strong antimuscarinic properties generally exhibited higher risk of DID.

CONCLUSIONS

With an incidence rate of <0.1%, the use of antidepressants and antipsychotics was rarely associated with DID within the Arzneimittelsicherheit in der Psychiatrie program. Tricyclic antidepressants and clozapine were the most commonly implicated psychotropic drugs. These data support the specific role of antimuscarinic properties in DID.

Cholinergic blockade of neuroinflammation – from tissue to RNA regulators

Inflammatory stimuli and consequent pro-inflammatory immune responses may facilitate neurodegeneration and threaten survival following pathogen infection or trauma, but potential controllers preventing these risks are incompletely understood. Here, we argue that small RNA regulators of acetylcholine (ACh) signaling, including microRNAs (miRs) and transfer RNA fragments (tRFs) may tilt the balance between innate and adaptive immunity, avoid chronic inflammation and prevent the neuroinflammation-mediated exacerbation of many neurological diseases. While the restrictive permeability of the blood–brain barrier (BBB) protects the brain from peripheral immune events, this barrier can be disrupted by inflammation and is weakened with age. The consequently dysregulated balance between pro- and anti-inflammatory processes may modify the immune activities of brain microglia, astrocytes, perivascular macrophages, oligodendrocytes and dendritic cells, leading to neuronal damage. Notably, the vagus nerve mediates the peripheral cholinergic anti-inflammatory reflex and underlines the consistent control of body–brain inflammation by pro-inflammatory cytokines, which affect cholinergic functions; therefore, the disruption of this reflex can exacerbate cognitive impairments such as attention deficits and delirium. RNA regulators can contribute to re-balancing the cholinergic network and avoiding its chronic deterioration, and their activities may differ between men and women and/or wear off with age. This can lead to hypersensitivity of aged patients to inflammation and higher risks of neuroinflammation-driven cholinergic impairments such as delirium and dementia following COVID-19 infection. The age- and sex-driven differences in post-transcriptional RNA regulators of cholinergic elements may hence indicate new personalized therapeutic options for neuroinflammatory diseases.

Overdose of Quetiapine-A Case Report with QT Prolongation

Quetiapine is an atypical antipsychotic drug used to treat bipolar disorder, schizophrenia, and major depressive disorder. Although several studies describe the adverse effects of intoxication with Quetiapine, only a few report an extreme overdose without comedications that lead to a life threat. We present a case of a 75-year-old male who tried to attempt suicide by ingesting 28 g of Quetiapine. During the management in the emergency department, both serum and urine samples were collected, allowing a complete pharmacokinetic analysis to be conducted, from the admission to the discharge.

Antimuscarinic Anticholinergic Medications in Parkinson Disease: To Prescribe or Deprescribe?

The relative importance of antimuscarinic anticholinergic medications for Parkinson's disease (PD) declined after the introduction of levodopa, such that anticholinergic medications are now much more likely to be prescribed for clinical indications other than parkinsonism. Recent studies have found an association between anticholinergic medication exposure and future risk of dementia in older individuals and those with PD. These findings provide a further reason to avoid the use of anticholinergic medications to treat motor symptoms of PD. More importantly, they raise the question of whether one of the goals of PD treatment should be to deprescribe all medications with anticholinergic properties, regardless of their indication, to reduce dementia risk. In this review, we discuss the use of anticholinergic medications in PD, the evidence supporting the association between anticholinergic medications and future dementia risk, and the potential implications of these findings for clinical care in PD.

Acute psychosis and serotonin syndrome in the setting of "Triple-C" overdose: a case report

Background

Over-the-counter medication overdose is a difficult diagnostic challenge for many physicians as common drug screening assays cannot detect these substances. We present a case of acute psychosis, serotonin syndrome, and anticholinergic overdose-like properties in the setting of Coricidin HBP Cough & Cold tablets, known by their street name Triple-C. This is the first case report we are aware of involving a patient presenting with these symptoms and requiring critical-care-level support.

Case presentation

A 31-year-old African American female with a past medical history of anxiety, childhood asthma, previous methamphetamine abuse, and coronavirus disease 2019 infection in August 2020 was brought to the emergency department by the local police department with altered mental status. Initial blood work, including extended drug screens, were unremarkable for a definitive diagnosis. This patient required critical-care-level support and high sedation because of her symptoms. Collateral history revealed the patient regularly consumed Triple-C daily for the 6 weeks prior to admission. A trial off sedation was attempted after 24 hours with no complications. The patient admitted to regular Triple-C consumption and auditory hallucinations since adolescence. She was discharged safely after 48 hours back into the community. She was lost to follow-up with psychiatry and internal medicine; however, she was evaluated in the emergency room 1 month later with a similar psychiatric presentation.

Conclusion

Overdose of Triple-C should be kept in the differential diagnosis of patients presenting with a triad of psychosis, serotonin syndrome, and anticholinergic overdose, in the setting of unknown substance ingestion.

Physostigmine should be used more readily for antimuscarinic toxicity: PRO

Physostigmine is the preferred treatment for antimuscarinic toxicity. Its use has a clear biological rationale and is supported by extensive clinical use which demonstrated effectiveness and safety.

Anticholinergic medication: Related dry mouth and effects on the salivary glands

OBJECTIVE

Salivary glands are among the most sensitive target organs of medications with anticholinergic (AC) properties, interrupting the neural stimulation of saliva secretion and reducing saliva flow. Hyposalivation results in dry mouth, leading to dental caries, intraoral infection, orofacial pain, problems with speaking and swallowing, and diminished oral health--related quality of life. Current understanding of the pharmacokinetics of AC medications and their effect on muscarinic receptors in the salivary glands were reviewed to assist clinicians in predicting salivary damage in patients with AC medication-induced dry mouth.

STUDY DESIGN

We summarized the literature related to the mechanisms and properties of AC medications, anticholinergic adverse effects, and their effect on salivary function and management strategies to prevent oral health damage.

RESULTS

Although a large number of studies reported on the frequencies of medication-induced dry mouth, we found very limited data on predicting individual susceptibility to AC medication--caused hyposalivation and no prospective clinical studies addressing this issue.

CONCLUSION

Dry mouth is most frequently caused by medications with AC properties, which interrupt the neural stimulation of saliva secretion. Interdisciplinary care should guide pharmacotherapeutics and dental interventions should aim in preventing AC salivary adverse effects and reducing the oral health burden from AC medication-induced dry mouth.

The Role of Dexmedetomidine in Pediatric Patients Presenting with an Anticholinergic Toxidrome

Background

We report two pediatric cases of anticholinergic toxidrome, including the youngest reported to date, in which standard therapeutic strategies were either contraindicated or ineffective, while treatment with dexmedetomidine was rapidly efficacious with no adverse effects. Moreover, with the recent shortage of physostigmine, we highlight an alternative treatment in this clinical setting. Case Summaries. In case 1, a two-year-old had an overdose presenting with an anticholinergic toxidrome. However, his hypopnea precluded the use of benzodiazepines due to the high likelihood of intubation. In case 2, a 14-year-old had a polypharmacy overdose inducing agitated delirium that was refractory to high-dose benzodiazepines. Due to the unknown ingestion, physostigmine was avoided. In both cases, dexmedetomidine helped the patient remain calm and metabolize the ingestions.

Conclusion

Our experience suggests that dexmedetomidine may be a useful adjunct in anticholinergic presentations in the setting of polypharmacy, when standard therapy is proven ineffective, contraindicated, or unavailable.

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

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

Prophylactic Physostigmine for Extreme and Refractory Adult Emergence Delirium, Aimed at Increasing Patient Safety and Reducing Health Care Workplace Violence: A Case Report

Emergence delirium is a well-known phenomenon that may be encountered after general anesthesia. A common approach to this issue is to risk stratify patients preoperatively and treat them postoperatively if emergence delirium occurs. We present the case of a patient with Barrett esophagus and a history of severe and refractory emergence delirium, who was successfully treated prophylactically with physostigmine, resulting in decreased risk of harm to the patient, trauma to the perioperative staff, and a safer and more positive recovery.

Associations Between Anticholinergic Medication Exposure and Adverse Health Outcomes in Older People with Frailty: A Systematic Review and Meta-analysis

Introduction

There are robust associations between use of anticholinergic medicines and adverse effects in older people. However, the nature of these associations for older people living with frailty is yet to be established.

Objectives

The aims were to identify and investigate associations between anticholinergics and adverse outcomes in older people living with frailty and to investigate whether exposure is associated with greater risks according to frailty status.

Methods

MEDLINE, CINAHL, EMBASE, Cochrane Database of Systematic Reviews, Web of Science and PsycINFO were searched to 1 August 2019. Observational studies reporting associations between anticholinergics and outcomes in older adults (average age ≥ 65 years) that reported frailty using validated measures were included. Primary outcomes were physical impairment, cognitive dysfunction, and change in frailty status. Risk of bias was evaluated using the Cochrane Risk of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. Meta-analysis was undertaken where appropriate.

Results

Thirteen studies (21,516 participants) were included (ten community, one residential aged-care facility and two hospital studies). Observed associations included reduced ability for chair standing, slower gait speeds, poorer physical performance, increased risk of falls and mortality. Conflicting results were reported for grip strength, timed up and go test, cognition and activities of daily living. No associations were observed for transitions between frailty states, psychological wellbeing or benzodiazepine-related adverse reactions. There was no clear evidence of differences in risks according to frailty status.

Conclusions

Anticholinergics are associated with adverse outcomes in older people living with frailty; however, the literature has significant methodological limitations. There is insufficient evidence to suggest greater risks based on frailty, and there is an urgent need to evaluate this further in well-designed studies stratifying by frailty.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00256-5.

Anticholinergic symptoms in a patient with a bupropion overdose successfully managed with physostigmine: a case report

We report the case of anticholinergic poisoning in a patient suffering from an overdose of bupropion. The patient presented with bilateral mydriasis, involuntary movements and signs of agitation. Bupropion is commonly used as antidepressant and smoking cessation aid. It inhibits neuronal reuptake of dopamine and norepinephrine and also antagonizes acetylcholine at the level of the nicotinic receptor sites. So far bupropion overdose resulting in symptoms mimicking an anticholinergic syndrome has rarely been reported in literature. In this case, one milligram of intravenous physostigmine, an acetylcholinesterase inhibitor, rapidly resolved patient agitation and mydriasis. This case indicates that physostigmine might be used as an antidote to quickly reverse the central and peripheral anticholinergic symptoms in patients with an overdose of bupropion. Erratum This article is the corrected version of the article published in issue 2020/3, pages 137-140. Typos and order of authors have now been corrected. With apologies to the authors.

Successful Treatment of an Acute High-Dose Clozapine Poisoning without Detoxication

Patient: Male, 28-year-old

Final Diagnosis: Clozapine poisoning

Symptoms: Drowsiness • hyperventilation • impaired consciousness • respiratory insufficiency • tachycadia

Medication: —

Clinical Procedure: —

Specialty: Critical Care Medicine • Psychiatry

The Use of Physostigmine in the Diagnosis and Treatment of Anticholinergic Toxicity After Olanzapine Overdose: Literature Review and Case Report

BACKGROUND

Second-generation antipsychotic agents are commonly used by clinicians for the treatment of various psychiatric and medical conditions. Despite their presumed safety, an overdose with olanzapine may lead to the development of anticholinergic toxicity. The anticholinergic toxidrome is characterized by both central and peripheral physical findings. Central anticholinergic syndrome, a term used to describe the symptoms that arise from reduced cholinergic activity in the central nervous system, is characterized primarily by signs and symptoms consistent with hyperactive delirium. Signs of peripheral anticholinergia include mydriasis and blurred vision, tremors, ataxia, fever/hyperthermia, flushed and dry skin, dry oral mucosa, decreased bowel sounds, constipation, and urinary retention, among other symptoms. In extreme cases, central anticholinergic syndrome can be associated with seizures, coma, respiratory failure, and cardiovascular collapse.

OBJECTIVE

To provide scientific evidence regarding the efficacy and safety of physostigmine use in cases of anticholinergic toxicity.

METHODS

We conducted a comprehensive review of the published literature on the symptoms, diagnosis, and treatment of anticholinergic toxicity.

RESULTS

Currently the recommended treatment for olanzapine overdose, as is the case of most severe anticholinergic toxicity cases, involves supportive care, along with cardiac, neurological, and respiratory status monitoring. In addition, we detail the symptoms characteristic of anticholinergic toxicity, using the case of a patient experiencing central anticholinergic syndrome after an overdose with olanzapine.

CONCLUSION

Physostigmine, a tertiary acetylcholinesterase inhibitor, can be used to assist in the both the diagnosis and management of severe anticholinergic toxicity associated with an olanzapine overdose, which might be applicable to the antimuscarinic toxidrome associated with the ingestion of agents with significant anticholinergic activity.

The Antiviral Drug Tilorone Is a Potent and Selective Inhibitor of Acetylcholinesterase

Acetylcholinesterase (AChE) is an important drug target in neurological disorders like Alzheimer's disease, Lewy body dementia, and Parkinson's disease dementia as well as for other conditions like myasthenia gravis and anticholinergic poisoning. In this study, we have used a combination of high-throughput screening, machine learning, and docking to identify new inhibitors of this enzyme. Bayesian machine learning models were generated with literature data from ChEMBL for eel and human AChE inhibitors as well as butyrylcholinesterase inhibitors (BuChE) and compared with other machine learning methods. High-throughput screens for the eel AChE inhibitor model identified several molecules including tilorone, an antiviral drug that is well-established outside of the United States, as a newly identified nanomolar AChE inhibitor. We have described how tilorone inhibits both eel and human AChE with IC₅₀'s of 14.4 nM and 64.4 nM, respectively, but does not inhibit the closely related BuChE IC₅₀ > 50 μM. We have docked tilorone into the human AChE crystal structure and shown that this selectivity is likely due to the reliance on a specific interaction with a hydrophobic residue in the peripheral anionic site of AChE that is absent in BuChE. We also conducted a pharmacological safety profile (SafetyScreen44) and kinase selectivity screen (SelectScreen) that showed tilorone (1 μM) only inhibited AChE out of 44 toxicology target proteins evaluated and did not appreciably inhibit any of the 485 kinases tested. This study suggests there may be a potential role for repurposing tilorone or its derivatives in conditions that benefit from AChE inhibition.

Physostigmine in Anticholinergic Poisoning: An Old Antidote With Resurgence

Physostigmine is a cholinesterase inhibitor used therapeutically in patients with anticholinergic delirium that is so severe that intubation may be required for airway protection. Given that a wide variety of medications have anticholinergic properties, and the current standard of care is typically a central nervous system depressant, hospitalizations are often lengthy and normally require a critical-care level of attention. Despite this, physostigmine is often underutilized and poorly understood in the clinical setting. We report a case of a 43-year-old female who presented to the emergency department one hour after ingesting approximately 150 tablets of diphenhydramine in a suicide attempt. She was treated with benzodiazepines with minimal success, and airway protection became imminent as her mentation continued to decline. Through the use of physostigmine, we were able to save this patient from endotracheal intubation and the potential complications of mechanical ventilation.

Anticholinergic symptoms in a patient with a bupropion overdose successfully managed with physostigmine: a case report

We report the case of anticholinergic poisoning in a patient suffering from an overdose of bupropion. The patient presented with bilateral mydriasis, involuntary movements and signs of agitation. Bupropion is commonly used as antidepressant and smoking cessation aid. It inhibits neuronal reuptake of dopamine and norepinephrine and also antagonizes acetylcholine at the level of the nicotinic receptor sites. So far bupropion overdose resulting in symptoms mimicking an anticholinergic syndrome has rarely been reported in literature. In this case, one milligram of intravenous physostigmine, an acetylcholinesterase inhibitor, rapidly resolved patient agitation and mydriasis. This case indicates that physostigmine might be used as an antidote to quickly reverse the central and peripheral anticholinergic symptoms in patients with an overdose of bupropion.

Dark Classics in Chemical Neuroscience: An Evidence-Based Systematic Review of Belladonna

Belladonna has diverse pharmacotherapeutic properties with a shadowy history of beauty, life, and death. Alkaloids present in belladonna have anti-inflammatory, anticholinergic, antispasmodic, mydriatic, analgesic, anticonvulsant, and antimicrobial activities, which makes it widely applicable for the treatment of various diseases. However, because of its associated toxicity, the medicinal use of belladonna is debatable. Therefore, an evidence-based systematic review was planned to elucidate the pharmacotherapeutic potential of belladonna. A comprehensive literature search was performed in PubMed, MEDLINE, the Cochrane database, Embase, and ClinicalTrials.gov using the keywords "belladonna", "belladonna and clinical trials", and "safety and efficacy of belladonna". Articles published from 1965 to 2020 showing the efficacy of belladonna in diverse clinical conditions are included. The quality of evidence was generated using the GRADE approach, and 20 studies involving 2302 patients were included for the systematic review. Our analyses suggest that belladonna treatment appears to be safe and effective in various disease conditions, including acute encephalitis syndrome, urethral stent pain, myocardial ischemia injury, airway obstructions during sleep in infants, climacteric complaints, irritable bowel syndrome, and throbbing headache. However, better understanding of the dosage and the toxicity of tropane alkaloids of belladonna could make it an efficient remedy for treating diverse medical conditions.

Post-operative functional neurological symptom disorder after anesthesia

A rare manifestation during the post-anesthetic period may include the occurrence of functional neurological symptom disorder (FNSD). FNSD is described as neurological symptoms that are not consistently explained by neurological or medical conditions. We report a case series consisting of six patients who underwent a general anesthetic at a tertiary referral hospital and experienced FNSD in the immediate post-anesthetic period. Life-threatening causes were excluded based on benign physical exam findings and knowledge of past history. Five of six cases manifested with FNSD only in the immediate post-operative setting after exposure to anesthesia, and never otherwise experienced these symptoms during their normal daily lives. MEDLINE and Google Scholar were searched through October 2019 using a highly-sensitive search strategy and identified 38 published cases of post-anesthetic FNSD. Meta-analysis of pooled clinical data revealed that a significant proportion of patients were females (86%), reported a history of psychiatric illness (49%), reported a prior history of FNSD (53%), and underwent general anesthesia as the primary anesthetic (93%). The majority of patients were exposed to diagnostic studies (66% received radiographic tests and 52% received electroencephalogram) as well as pharmacologic therapy (57%). While no deaths occurred, many patients had unanticipated admission to the hospital (53%) or to the intensive care unit (25%). These data may help inform the anesthesia literature on presentation, risk factors, and treatment outcomes of FNSD in the context of anesthetic administration. We contemplate whether anesthetic agents may predispose a vulnerable brain to manifest with involuntary motor and sensory control seen in FNSD.

Comparative physiology and efficacy of atropine and scopolamine in sarin nerve agent poisoning

Anticholinergic treatment is key for effective medical treatment of nerve agent exposure. Atropine is included at a 2 mg intramuscular dose in so-called autoinjectors designed for self- and buddy-aid. As patient cohorts are not available, predicting and evaluating the efficacy of medical countermeasures relies on animal models. The use of atropine as a muscarinic antagonist is based on efficacy achieved in studies in a variety of species. The dose of atropine administered varies considerably across these studies. This is a complicating factor in the prediction of efficacy in the human situation, largely because atropine dosing also influences therapeutic efficacy of oximes and anticonvulsants generally part of the treatment administered. To improve translation of efficacy of dosing regimens, including pharmacokinetics and physiology provide a promising approach. In the current study, pharmacokinetics and physiological parameters obtained using EEG and ECG were assessed in naïve rats and in sarin-exposed rats for two anticholinergic drugs, atropine and scopolamine. The aim was to find a predictive parameter for therapeutic efficacy. Scopolamine and atropine showed a similar bioavailability, but brain levels reached were much higher for scopolamine. Scopolamine exhibited a dose-dependent loss of beta power in naïve animals, whereas atropine did not show any such central effect. This effect was correlated with an enhanced anticonvulsant effect of scopolamine compared to atropine. These findings show that an approach including pharmacokinetics and physiology could contribute to improved dose scaling across species and assessing the therapeutic potential of similar anticholinergic and anticonvulsant drugs against nerve agent poisoning.

Delirium in hospitalised children

Delirium is a syndrome characterised by an acute and fluctuating alteration in cognition and awareness. It occurs frequently in children with serious medical illness, and is associated with adverse outcomes such as increased length of hospital stay, duration of mechanical ventilation, hospital costs, and mortality. Delirium-especially the hypoactive subtype-is often overlooked by paediatric practitioners, but can be reduced by mitigating risks and effectively managed if detected early. Non-modifiable risk factors of delirium include young age (age <2 years), cognitive or neurological disabilities, need for invasive mechanical ventilation, severe underlying illness and pre-existing chronic conditions, and poor nutritional status. Routine bedside screening using validated tools can enable early detection of delirium. To reduce delirium in hospitalised children, health-care providers should optimise the hospital environment (eg, by reducing sleep disruption and keeping the child stimulated during the day), improve pain management, and decrease sedation (particularly use of benzodiazepines).