Adverse Effects of Physostigmine

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.

[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.

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.

[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.

Disruption of hippocampal neuronal circuit function depends upon behavioral state in the APP/PS1 mouse model of Alzheimer's disease

The Alzheimer's disease-associated peptide amyloid-beta (Aβ) has been associated with neuronal hyperactivity under anesthesia, but clinical trials of anticonvulsants or neural system suppressors have, so far, failed to improve symptoms in AD. Using simultaneous hippocampal calcium imaging and electrophysiology in freely moving mice expressing human Aβ, here we show that Aβ aggregates perturbed neural systems in a state-dependent fashion, driving neuronal hyperactivity in exploratory behavior and slow wave sleep (SWS), yet suppressing activity in quiet wakefulness (QW) and REM sleep. In exploratory behavior and REM sleep, Aβ impaired hippocampal theta-gamma phase-amplitude coupling and altered neuronal synchronization with theta. In SWS, Aβ reduced cortical slow oscillation (SO) power, the coordination of hippocampal sharp wave-ripples with both the SO and thalamocortical spindles, and the coordination of calcium transients with the sharp wave-ripple. Physostigmine improved Aβ-associated hyperactivity in exploratory behavior and hypoactivity in QW and expanded the range of gamma that coupled with theta phase, but exacerbated hypoactivity in exploratory behavior. Together, these findings show that the effects of Aβ alone on hippocampal circuit function are profoundly state dependent and suggest a reformulation of therapeutic strategies aimed at Aβ induced hyperexcitability.

Datura poisoning in a family: Case series and literature review

Datura spp. is a potentially poisonous plant that is widely spread and is simply accessible, which can yield poisoning with a central and peripheral anticholinergic effect. We reported cases of family poisoning caused by the herbal tea with refreshing effects that were identified as Datura spp.

Datura spp. and many other complementary medicine products are potentially poisonous or could cause adverse effects or interact with prescribed medications. The herbal medicine business is not well regulated and has the potential to cause significant harm. Physicians must routinely gain a history of the use of herbal products.

Natural Products from Plants and Algae for Treatment of Alzheimer’s Disease: A Review

Neurodegenerative disorders including Parkinson’s disease (PD), Huntington’s disease (HD) and the most frequent, Alzheimer’s disease (AD), represent one of the most urgent medical needs worldwide. Despite a significantly developed understanding of disease development and pathology, treatments that stop AD progression are not yet available. The recent approval of sodium oligomannate (GV-971) for AD treatment in China emphasized the potential value of natural products for the treatment of neurodegenerative disorders. Many current clinical studies include the administration of a natural compound as a single and combination treatment. The most prominent mechanisms of action are anti-inflammatory and anti-oxidative activities, thus preserving cellular survival. Here, we review current natural products that are either approved or are in testing for a treatment of neurodegeneration in AD. In addition to the most important compounds of plant origin, we also put special emphasis on compounds from algae, given their neuroprotective activity and their underlying mechanisms of neuroprotection.

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.

Systemic side effects of glaucoma medications

Glaucoma is a progressive loss of retinal ganglion cells leading to visual field loss. Lowering intraocular pressure is currently the only modifiable risk factor to slow glaucoma progression. Intraocular pressure-lowering options include topical and systemic medications, lasers, and surgical procedures. Glaucoma eye drops play a major role in treating this blinding disease. Similar to all medications, the glaucoma medications have their own adverse effects. The majority of glaucoma medications work by stimulating or inhibiting adrenergic, cholinergic, and prostaglandin receptors, which are distributed all over the body. Therefore, the glaucoma medications can affect organs other than the eye. This review will discuss the systemic adverse effects of carbonic anhydrase inhibitors, sympathomimetics, para-sympathomimetics, beta blockers, prostaglandin analogs, hyperosmotic agents, and novel glaucoma medications with a stress on pregnant patients, breastfeeding mothers, and paediatric patients.

A Case of Massive Diphenhydramine and Naproxen Overdose

BACKGROUND

Diphenhydramine, a first generation H₁ histamine receptor antagonist, is a commonly used nonprescription medication that is used for the treatment of allergy, as a sleep aid, or combined with cough and cold remedies. Naproxen, a nonsteroidal anti-inflammatory drug (NSAID), is used commonly for analgesia. Although most cases of diphenhydramine or naproxen overdose require excellent supportive care only, meticulous attention should be given to cardiovascular and neurologic status.

CASE REPORT

A 22-year-old woman presented with altered mental status secondary to intentional ingestion of 240 combination caplets of naproxen sodium 220 mg and diphenhydramine hydrochloride 25 mg. While in the emergency department, she manifested a wide-complex tachycardia in the setting of hypotension that required repeated administration of sodium bicarbonate to overcome the sodium channel blockade caused by diphenhydramine. Aggressive potassium repletion was performed simultaneously. Her clinical course was complicated by status-epilepticus that required intubation. Orogastric lavage was performed, which returned blue pill slurry consistent with the ingested caplets. The patient was extubated on hospital day 2 and transferred to psychiatry thereafter. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In light of recent social media trends, such as the "Benadryl challenge" and its widespread availability, emergency providers should be familiar with diphenhydramine toxicity, especially the life-threatening neurologic consequences and risk of cardiovascular collapse. NSAIDs, such as naproxen, and other nonprescription analgesics are becoming more and more important in light of the current opioid crisis. There should be an emphasis on understanding these medications and their potential implications when taken in overdose.

The Carbamate, Physostigmine does not Impair Axonal Transport in Rat Cortical Neurons

Among the various chemicals that are commonly used as pesticides, organophosphates (OPs), and to a lesser extent, carbamates, are most frequently associated with adverse long-term neurological consequences. OPs and the carbamate, pyridostigmine, used as a prophylactic drug against potential nerve agent attacks, have also been implicated in Gulf War Illness (GWI), which is often characterized by chronic neurological symptoms. While most OP- and carbamate-based pesticides, and pyridostigmine are relatively potent acetylcholinesterase inhibitors (AChEIs), this toxicological mechanism is inadequate to explain their long-term health effects, especially when no signs of acute cholinergic toxicity are exhibited. Our previous work suggests that a potential mechanism of the long-term neurological deficits associated with OPs is impairment of axonal transport (AXT); however, we had not previously evaluated carbamates for this effect. Here we thus evaluated the carbamate, physostigmine (PHY), a highly potent AChEI, on AXT using an in vitro neuronal live imaging assay that we have previously found to be very sensitive to OP-related deficits in AXT. We first evaluated the OP, diisopropylfluorophosphate (DFP) (concentration range 0.001-10.0 µM) as a reference compound that we found previously to impair AXT and subsequently evaluated PHY (concentration range 0.01-100 nM). As expected, DFP impaired AXT in a concentration-dependent manner, replicating our previously published results. In contrast, none of the concentrations of PHY (including concentrations well above the threshold for impairing AChE) impaired AXT. These data suggest that the long-term neurological deficits associated with some carbamates are not likely due to acute impairments of AXT.

Current Quest in Natural Bioactive Compounds for Alzheimer's Disease: Multi-Targeted-Designed-Ligand Based Approach with Preclinical and Clinical Based Evidence

Alzheimer's disease is a common and most chronic neurological disorder (NDs) associated with cognitive dysfunction. Pathologically, Alzheimer's disease (AD) is characterized by the presence of β-amyloid (Aβ) plaques, hyper-phosphorylated tau proteins, and neurofibrillary tangles, however, persistence oxidative-nitrative stress, endoplasmic reticulum stress, mitochondrial dysfunction, inflammatory cytokines, pro-apoptotic proteins along with altered neurotransmitters level are common etiological attributes in its pathogenesis. Rivastigmine, memantine, galantamine, and donepezil are FDA approved drugs for symptomatic management of AD, whereas tacrine has been withdrawn because of hepatotoxic profile. These approved drugs only exert symptomatic relief and exhibit poor patient compliance. In the current scenario, the number of published evidence shows the neuroprotective potential of naturally occurring bioactive molecules via their antioxidant, anti-inflammatory, antiapoptotic and neurotransmitter modulatory properties. Despite their potent therapeutic implications, concerns have arisen in context to their efficacy and probable clinical outcome. Thus, to overcome these glitches, many heterocyclic and cyclic hydrocarbon compounds inspired by natural sources have been synthesized and showed improved therapeutic activity. Computational studies (molecular docking) have been used to predict the binding affinity of these natural bioactive as well as synthetic compounds derived from natural sources for the acetylcholine esterase, α/β secretase Nuclear Factor kappa- light-chain-enhancer of activated B cells (NF-kB), Nuclear factor erythroid 2-related factor 2(Nrf2) and other neurological targets. Thus, in this review, we have discussed the molecular etiology of AD, focused on the pharmacotherapeutics of natural products, chemical and pharmacological aspects and multi-targeted designed ligands (MTDLs) of synthetic and semisynthetic molecules derived from the natural sources along with some important on-going clinical trials.

Cholinergic System and Its Therapeutic Importance in Inflammation and Autoimmunity

Neurological and immunological signals constitute an extensive regulatory network in our body that maintains physiology and homeostasis. The cholinergic system plays a significant role in neuroimmune communication, transmitting information regarding the peripheral immune status to the central nervous system (CNS) and vice versa. The cholinergic system includes the neurotransmitter\ molecule, acetylcholine (ACh), cholinergic receptors (AChRs), choline acetyltransferase (ChAT) enzyme, and acetylcholinesterase (AChE) enzyme. These molecules are involved in regulating immune response and playing a crucial role in maintaining homeostasis. Most innate and adaptive immune cells respond to neuronal inputs by releasing or expressing these molecules on their surfaces. Dysregulation of this neuroimmune communication may lead to several inflammatory and autoimmune diseases. Several agonists, antagonists, and inhibitors have been developed to target the cholinergic system to control inflammation in different tissues. This review discusses how various molecules of the neuronal and non-neuronal cholinergic system (NNCS) interact with the immune cells. What are the agonists and antagonists that alter the cholinergic system, and how are these molecules modulate inflammation and immunity. Understanding the various functions of pharmacological molecules could help in designing better strategies to control inflammation and autoimmunity.

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.

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.

Natural and synthetic drugs used for the treatment of the dementia

This review is devoted to comparative pharmacological analysis of synthetic drugs such as memantine and its isomers, as well as tacrine, velnacrine, rivastigmine, and donepezil, with natural alkaloids, terpenoids, and triterpenoid peroxides, which are used to treat dementia, Alzheimer's and Parkinson's diseases, myasthenia gravis and other neurodegenerative diseases. Recently discovered by French scientists from Marseille triterpenoid hydroperoxides demonstrate high activity as potential therapeutic agents for the treatment of dementia. The information presented in this review is of great interest to pharmacologists, medical chemists, physiologists, neurologists and doctors, as well as for the pharmaceutical industry.

[Diagnostics and treatment of selected clinically relevant, acute drug intoxications]

Acute drug poisoning due to accidental or self-damaging overdoses is responsible for 5-10% of emergency medical interventions in Germany. The treatment of asymptomatic to life-threatening courses requires extensive expertise. On the basis of a selective literature search, this article gives an overview of selected clinically relevant, acute drug poisonings with regard to epidemiology, symptomatology, diagnostics, and therapy.Intoxications with psychotropic drugs are the most common drug intoxications. Poisoning with tricyclic antidepressants causes anticholinergic, central nervous, and cardiovascular symptoms. Less toxic are selective serotonin reuptake inhibitors (SSRIs); the intoxication may be characterized by serotonin syndrome. Malignant neuroleptic syndrome is a severe complication of neuroleptic poisoning.Poisoning with analgesics is clinically relevant due to its high availability. For paracetamol poisoning, intravenous acetylcysteine is available as an antidote. Hemodialysis may be indicated for severe salicylate intoxication. Poisoning with nonsteroidal anti-inflammatory drugs is usually only associated with mild signs of intoxication.Poisoning with cardiac drugs (β-blockers and calcium antagonists) can cause life-threatening cardiovascular events. In addition to symptomatic therapy, insulin glucose therapy also plays an important role.The majority of acute drug poisonings can be treated adequately by symptomatic and partly intensive care therapy - if necessary with the application of primary and secondary toxin elimination. Depending on the severity of the intoxication, pharmacology-specific therapy must be initiated.