Anticholinergic syndrome represents one of the most critical and classically encountered toxidromes in clinical toxicology, emergency medicine, and psychopharmacology. Arising from acute or cumulative competitive antagonism of muscarinic acetylcholine receptors throughout the central and autonomic nervous systems, this clinical entity encompasses a profound constellation of peripheral dysautonomia and neurocognitive disruption. Rapid identification and targeted intervention are paramount, as untreated anticholinergic toxicity carries substantial morbidity ranging from hyperthermic multiorgan failure to life-threatening agitated delirium.
Anticholinergic Syndrome
1. Concise Definition
Anticholinergic syndrome is an acute, potentially life-threatening toxidrome precipitated by the competitive inhibition of endogenous acetylcholine at central and peripheral muscarinic receptor sites. It is clinically characterized by a distinct constellation of autonomic failure—including hyperthermia, severe mucosal dryness, anhidrosis, mydriasis, and tachycardia—coupled with profound central nervous system dysfunction manifest as agitation, visual hallucinations, and fluctuating delirium.
Pharmacologically, the syndrome stems from the exposure to exogenous compounds that possess high affinity but zero intrinsic efficacy at muscarinic acetylcholine receptors (M1 through M5). While classically associated with intentional self-poisoning or pediatric accidental ingestion of belladonna alkaloids or over-the-counter sedatives, the condition increasingly manifests as an insidious, cumulative phenomenon in geriatric cohorts secondary to iatrogenic polypharmacy, commonly designated as acute-on-chronic anticholinergic cognitive toxicity.
2. Etymology & Linguistic Origin
The term anticholinergic is a modern hybrid neologism synthesized from classical Greek roots. The prefix anti- originates from the Ancient Greek ἀντί (antí), signifying “against,” “in opposition to,” or “counter.” The root cholin- traces to the Greek χολή (kholē), meaning “bile,” which was historically applied to choline upon its original isolation from bovine bile by German chemist Adolph Strecker in 1862. The suffix -ergic derives from the Greek ἔργον (érgon), denoting “work,” “action,” or “activity.”
When combined, “anticholinergic” denotes an agent or physiological state that counteracts the actions mediated by choline derivatives, specifically acetylcholine. The word syndrome is directly borrowed from the Greek συνδρομή (sundromē), composed of σύν (sun, “together”) and δρόμος (drómos, “a running” or “course”), literally translating to “a running together” of symptoms that characterize a distinct morbid process. The term entered standardized pharmacological taxonomy during the mid-twentieth century as neurochemists systematically differentiated muscarinic and nicotinic transmission pathways.
3. Pronunciation & Grammatical Form
The term is phonetically transcribed in standard International Phonetic Alphabet (IPA) as /ˌæn.tiˌkoʊ.ləˈnɜːr.dʒɪk ˈsɪn.droʊm/ in General American English, or /ˌæn.tiˌkɒl.ɪˈnɜː.dʒɪk ˈsɪn.drəʊm/ in Received Pronunciation.
Grammatically, “anticholinergic syndrome” operates as a compound clinical noun phrase. In medical prose, “anticholinergic” acts as an attributive adjective modifying the head noun “syndrome” (e.g., “the patient presented with profound anticholinergic toxicity”). It may also be nominalized in plural form to designate the pharmacologic class itself (e.g., “prescribing anticholinergics to vulnerable populations”). Synonymous expressions within critical care literature include “anticholinergic toxidrome” and “muscarinic receptor antagonist toxicity.”
4. Detailed Conceptual Explanation
To understand anticholinergic syndrome, one must examine the pervasive physiological footprint of acetylcholine (acetylcholine) within the human body. Acetylcholine functions as the primary neurotransmitter of the parasympathetic nervous system, the preganglionic autonomic pathways, the somatic neuromuscular junctions, and diverse projecting pathways within the central nervous system. Anticholinergic syndrome specifically entails the blockade of muscarinic acetylcholine receptors (mAChRs), which are G-protein coupled receptors divided into five distinct subtypes (M1–M5), while largely sparing nicotinic ionotropic receptors.
Peripheral manifestations emerge from the blockade of M2 and M3 receptors situated across autonomic effector organs. M2 receptors reside predominantly within the cardiac sinoatrial and atrioventricular nodes; their antagonism abrogates intrinsic vagal parasympathetic braking mechanisms, precipitating sinus tachycardia. M3 receptors govern the secretomotor functions of salivary, lacrimal, and eccrine sweat glands, as well as the contractile tone of visceral smooth muscle in the gastrointestinal and urogenital tracts. Consequently, muscarinic antagonism induces anhidrosis (cessation of sweating), absolute xerostomia (dry mouth), urinary bladder detrusor muscle relaxation causing urinary retention, and profound inhibition of enteric peristalsis culminating in paralytic ileus. The loss of pupillary pupilloconstrictor tone produces passive, non-reactive mydriasis accompanied by cycloplegia, rendering the patient unable to accommodate for near vision.
Centrally, M1, M4, and M5 receptors are densely distributed within the neocortex, hippocampus, basal forebrain, and striatum, areas essential for arousal, memory consolidation, attention, and motor integration. Antagonism of these cerebral muscarinic networks disrupts ascending cholinergic reticular activating inputs, leading to an acute brain failure state. The neurobehavioral profile transitions rapidly from anxiety, emotional lability, and confusion to a hyperactive encephalopathy characterized by fragmented speech, disorientation, and stereotypical purposeless picking movements directed at real or imaginary objects (floccillation and carphologia).
The boundaries of the syndrome depend heavily upon the causative xenobiotic’s volume of distribution, lipid solubility, and blood-brain barrier permeability. Quaternary amines (such as ipratropium) remain polarized and poorly penetrate the blood-brain barrier, triggering predominantly peripheral anticholinergic manifestations. Conversely, lipophilic tertiary amines (such as scopolamine, atropine, diphenhydramine, and tricyclic antidepressants) cross effortlessly into the central nervous system, driving devastating neuropsychiatric delirium alongside systemic autonomic deregulation.
5. Historical Development
The clinical recognition of anticholinergic toxicity predates modern pharmacology by several millennia, rooted in the ethnobotanical utilization and accidental poisonings associated with the Solanaceae (nightshade) plant family. Ancient civilizations across the Mediterranean, Asia, and the Americas documented the profound delirifacient, cycloplegic, and hyperthermic properties of species such as Atropa belladonna (Deadly Nightshade), Hyoscyamus niger (Henbane), Mandragora officinarum (Mandrake), and various Datura species.
In the Renaissance, Venetian women exploited the extract of Atropa belladonna to induce bilateral mydriasis for cosmetic enhancement—giving the plant its species name (“beautiful lady”). However, excessive systemic absorption frequently resulted in toxic delirium and violent behavioral excitation, phenomena documented by medieval naturalists and early modern toxicologists. In 1831, the German pharmacist Heinrich F. G. Mein succeeded in isolating pure crystalline atropine from belladonna roots, enabling the transition from empirical botanical toxicology to quantitative receptor pharmacology.
During the early twentieth century, Nobel laureates Sir Henry Hallett Dale and Otto Loewi systematically elucidated the neurochemical properties of acetylcholine and differentiated its actions into “muscarinic” and “nicotinic” categories. As synthetic organic chemistry flourished in the mid-twentieth century, an expansive array of therapeutic agents inadvertently incorporated anticholinergic pharmacophores. The advent of phenothiazine antipsychotics, tricyclic antidepressants, and first-generation H1-antihistamines in the 1950s and 1960s resulted in a dramatic surge in hospitalizations for drug-induced delirium and dysautonomia.
In the 1970s, toxicologists such as Howard Mofenson and Joseph Greensher formalized the concept of “toxidromes” (toxic syndromes), cementing anticholinergic syndrome as an archetypal diagnostic pattern. Simultaneously, the discovery of physostigmine’s central acetylcholinesterase-inhibiting properties in 1864 by Thomas Richard Fraser led to its revival in the late twentieth century as an antidote capable of crossing the blood-brain barrier to reverse both peripheral and central components of the syndrome.
6. Theoretical Foundations
The modern conceptualization of anticholinergic syndrome rests upon the classic principles of competitive antagonism, receptor occupancy theory, and central neurochemical equilibrium. At the cellular level, muscarinic antagonists act as orthosteric competitive antagonists or inverse agonists. By reversibly binding to the same active site as the endogenous agonist acetylcholine without triggering G-protein activation, they shift the dose-response curve to the right. The severity of the clinical syndrome reflects the fraction of receptors occupied by the antagonist relative to endogenous synaptic concentrations of acetylcholine.
Within the central nervous system, cholinergic pathways interact continuously with dopaminergic, gamma-aminobutyric acid (GABA)-ergic, and glutamatergic networks. The Cholinergic Hypothesis of Cognitive Functioning emphasizes that adequate septohippocampal and basocortical cholinergic transmission is prerequisite for attention, encoding, and sensory gating. When muscarinic receptors are blocked, unrestrained dopaminergic and monoaminergic tone emerges within the limbic system and striatum. This functional imbalance is theoretically identical to the neurochemical cascade observed in primary psychotic states and idiopathic hyperactive delirium, providing a mechanistic explanation for the florid auditory and visual hallucinations characteristic of the toxidrome.
Furthermore, thermoregulatory theory elucidates the lethal potential of the syndrome. Eccrine sweating represents the human body’s primary physiological mechanism for evaporative heat dissipation. Blockade of postganglionic sympathetic cholinergic fibers innervating sweat glands completely cripples sweat secretion. Concurrently, behavioral agitation and internal metabolic hyperproduction generate substantial endogenous caloric energy, leading to rapidly escalating, uncompensated core hyperthermia that destabilizes enzymatic machinery and damages capillary endothelia.
7. Key Components, Types & Dimensions
The clinical features of anticholinergic syndrome are classically organized into peripheral and central domains, historically summarized by the diagnostic medical mnemonic: “Blind as a bat, mad as a hatter, red as a beet, hot as a hare, dry as a bone, the bowel and bladder lose their tone, and the heart runs alone.”
- Peripheral Manifestations:
- Tachycardia: Sinus tachycardia typically represents the earliest and most sensitive objective physiological sign of parasympathetic blockade, driven by the inhibition of vagal tone on the sinoatrial node.
- Hyperthermia: Core body temperature elevation driven by total anhidrosis combined with muscular agitation; core temperatures may exceed 41°C (105.8°F), mimicking heat stroke.
- Anhidrosis & Mucosal Dryness: Distinctively dry, parched oral mucosa, absent axillary moisture, and warm, arid skin secondary to sweat gland denervation.
- Mydriasis & Cycloplegia: Severe pupillary dilation resulting in photophobia and complete loss of visual accommodation, leading to blurred near vision.
- Flushed Skin: Cutaneous vasodilation (“red as a beet”), predominantly over the face, neck, and upper trunk, representing compensatory reflexive thermal shunting to radiate core heat in the absence of evaporative perspiration.
- Urinary Retention: Bladder distension secondary to detrusor smooth muscle relaxation and internal urethral sphincter constriction, predisposing to bladder rupture or post-renal acute kidney injury.
- Hypoactive or Absent Bowel Sounds: Gastric atony and suppressed peristalsis resulting in progressive abdominal distension, obstipation, and the potential for paralytic ileus.
- Central Nervous System Manifestations:
- Anticholinergic Delirium: Fluctuating, hyperactive delirium characterized by acute cognitive disorientation, marked executive dysfunction, and fragmented speech.
- Perceptual Distortions: Highly characteristic micro-hallucinations, lilliputian visions, and tactile hallucinations (e.g., sensations of insects crawling under the skin, termed formication).
- Purposeless Stereotypical Behaviors: Incessant grabbing, plucking at empty air, or picking at bed linens (carphologia and floccillation), often accompanied by repetitive occupational pantomimes.
- Severe Neurotoxicity: At toxic thresholds, severe agitation can degenerate into myoclonus, choreoathetosis, generalized tonic-clonic seizures, profound central respiratory depression, coma, and cardiorespiratory arrest.
8. Examples & Illustrative Cases
To contextualize anticholinergic syndrome in clinical practice, consider the following representative clinical archetypes:
Case Illustration 1: The Intentional Over-the-Counter Ingestion
A 17-year-old adolescent presents to the emergency department after ingesting approximately 1,250 mg of diphenhydramine in an episode of deliberate self-harm. Upon arrival, the patient is disoriented to time and place, vigorously attempting to grasp invisible strings suspended from the ceiling. Vital signs reveal a heart rate of 142 beats per minute, blood pressure of 148/92 mmHg, respiratory rate of 22 breaths per minute, and a rectal core temperature of 38.6°C. Physical examination confirms wildly dilated, poorly reactive pupils, dry axillae, completely parched oral membranes with absence of saliva pooling, absent bowel sounds, and a palpable suprapubic fullness confirmed by bedside ultrasonography as 950 mL of retained urine. This presentation is the textbook acute severe anticholinergic toxidrome resulting from an over-the-counter first-generation ethanolamine antihistamine.
Case Illustration 2: Accidental Ethnobotanical Ingestion
A 21-year-old recreational forager consumes a brewed tea prepared from the seeds of Datura stramonium (Jimson weed) seeking hallucinogenic experiences. Within two hours, companion witnesses report rapid speech progressing to incoherent babbling, aggressive agitation, and total disrobing due to complaints of burning heat. Upon emergency service contact, the patient is combative, exhibiting deep facial erythema, dry crimson skin without a trace of sweat, wide mydriasis, and a core temperature of 39.8°C. This presentation illustrates classic plant-based alkaloid poisoning rich in scopolamine, hyoscyamine, and atropine.
Case Illustration 3: The Cumulative Geriatric Anticholinergic Cascade
An 82-year-old female with mild vascular cognitive impairment, overactive bladder, allergic rhinitis, and insomnia is prescribed oxybutynin, hydroxyzine, and paroxetine concurrently. Over two weeks, family members note progressive cognitive decline, daytime lethargy punctuated by nocturnal wandering, visual hallucinations of unfamiliar animals in her hallway, and worsening constipation. Upon clinical presentation, she is disoriented, tachycardic at 104 beats per minute, has no axillary sweat, and demonstrates significant post-void urinary residual volumes. Withdrawal of the offending agents yields complete resolution of the hallucinations and cognitive baseline restitution, demonstrating the insidious nature of cumulative anticholinergic burden in the elderly.
9. Measurement & Assessment
The diagnosis of anticholinergic syndrome is fundamentally clinical, synthesized from careful history, physical examination, and deliberate autonomic evaluation. Because quantitative serum assays for specific anticholinergic agents are rarely available on a stat basis, clinicians rely heavily on diagnostic algorithms, physiological indicators, and validated pharmacological risk scoring tools.
Bedside physiological assessment begins with the thorough examination of cutaneous hydration (particularly in the axillae and groin) and the presence of mucosal moisture beneath the tongue. The concurrent finding of dry skin and sinus tachycardia in an acutely agitated patient provides high predictive specificity for anticholinergic toxicity over competing toxidromes. Diagnostic instrumentation includes bedside ultrasonography to quantify urinary retention within the bladder and continuous electrocardiographic monitoring to detect underlying cardiac conduction disturbances (e.g., sodium channel blockade characterized by QRS prolongation, commonly seen with tricyclic antidepressants).
In geriatric and chronic care domains, cumulative anticholinergic exposure is quantified utilizing formalized scales such as the Anticholinergic Cognitive Burden (ACB) Scale, the Anticholinergic Drug Scale (ADS), and the Anticholinergic Risk Scale (ARS). These validated instruments stratify medications on an ordinal scale from 0 (no known anticholinergic activity) to 3 (marked central or peripheral anticholinergic potency). Cumulative scores exceeding 3 are robustly correlated with acute confusional episodes, elevated fracture risks due to falls, and accelerated cognitive decline.
Finally, a targeted diagnostic challenge with the reversible acetylcholinesterase inhibitor physostigmine salicylate serves as an in vivo diagnostic assay. When administered slowly under strict cardiac monitoring to a patient exhibiting both peripheral and central signs without confounding cardiac conduction delays, rapid temporary clearance of the delirium and normalization of vital signs confirms an anticholinergic etiology.
10. Applications & Practical Significance
Recognizing and managing anticholinergic syndrome has direct therapeutic implications across clinical toxicology, emergency resuscitation, and acute psychiatric triage. In critical care environments, failure to identify the toxidrome can lead to inappropriate interventions, such as administering low-potency neuroleptics (e.g., chlorpromazine or haloperidol) for agitation, which paradoxically amplifies the anticholinergic blockade, worsens hypothermia dissipation, and precipitates torsades de pointes or lethal hyperthermia.
Clinical management prioritizes rigorous supportive measures:
- Airway and Metabolic Stabilization: Sedation of agitated delirium using intravenous GABA-A receptor agonists (specifically benzodiazepines such as lorazepam or diazepam) blunts autonomic hyperactivity and mitigates the genesis of exertional rhabdomyolysis.
- Aggressive Evaporative Cooling: In the presence of hyperthermia, active external cooling with misting, fans, and cooling blankets must be deployed instantly to shield the cerebral and renal vasculature from heat-shock denaturative injury.
- Targeted Decontamination and Drainage: Because anticholinergics dramatically delay gastric emptying, mechanical interventions such as the placement of an indwelling urinary catheter are mandatory to treat painful, delirium-fueling urinary retention. Activated charcoal can be considered well beyond standard administration windows in awake patients or those with secured airways.
- Antidotal Therapy with Physostigmine: Physostigmine salicylate represents the primary specific reversal agent. Unlike neostigmine or pyridostigmine, physostigmine’s non-polar tertiary amine structure allows rapid penetration of the blood-brain barrier. By reversibly inhibiting acetylcholinesterase, it preserves endogenous synaptic acetylcholine, outcompeting the xenobiotic antagonist at both central and peripheral receptors. Recommended adult dosing is 0.5 to 2.0 mg infused intravenously over at least five minutes, accompanied by continuous ECG monitoring and bedside atropine to manage inadvertent cholinomimetic bradycardia or excessive bronchorrhea.
11. Research & Empirical Evidence
Decades of empirical studies have analyzed the morbidity, prognostic trajectories, and therapeutic modalities of anticholinergic syndrome. Toxicological literature has firmly established the efficacy of physostigmine over benzodiazepine monotherapy in resolving anticholinergic delirium. In a pivotal comparative study by Burns and colleagues (2000), physostigmine controlled agitation and cleared cognitive impairment significantly faster (efficacy exceeding 90%) than diazepam (efficacy near 24%), while simultaneously lowering the rate of secondary complications and intensive care unit admissions.
Extensive observational and pharmacovigilance studies, such as the prospective trials led by Boustani et al. and longitudinal cohort investigations by Gray and colleagues (2015), have illuminated the long-term neurocognitive perils of protracted anticholinergic exposure. Gray et al. demonstrated a statistically significant dose-dependent association between cumulative 10-year anticholinergic use and incident all-cause dementia and Alzheimer’s disease in community-dwelling older adults. These findings have repositioned anticholinergic load from a transient toxicological nuisance to an established, modifiable neurodegenerative risk factor.
Contemporary emergency medicine trials focus on refining the safety indications for antidotal therapy. Historically, concerns regarding physostigmine-induced asystole—stemming primarily from its indiscriminate use in tricyclic antidepressant overdoses during the 1970s and 1980s—diminished its clinical utilization. However, multi-center registry data published by toxicologists through the Toxicology Investigators Consortium (ToxIC) demonstrate that in isolated anticholinergic toxidromes lacking electrocardiographic conduction disturbances (QRS duration < 100 ms), physostigmine exhibits an exceptional safety profile with negligible incidences of malignant bradyarrhythmias.
12. Cultural & Cross-Cultural Considerations
The cultural contexts underpinning anticholinergic toxicity vary substantially across geographical and demographic landscapes. In indigenous and traditional societies, anticholinergic intoxication frequently emerges from the sacramental, shamanic, or recreational consumption of native solanaceous plants. For instance, in parts of South America, the historical administration of Brugmansia (angel’s trumpet) infusions in religious rites or criminal enticements (locally designated as “burundanga” or scopolamine drugging) represents a distinct cross-cultural clinical presentation with high exposure risks for foreign travelers.
In North America and Europe, cultural trends among adolescents and young adults frequently cycle through intentional recreational abuse of over-the-counter anticholinergics, popularized periodically by viral social media trends (e.g., the “Benadryl Challenge”). Such viral phenomena reflect modern vectors of epidemic toxicity driven by peer networks rather than traditional ritual use. Furthermore, disparities in global pharmaceutical regulation influence incidence: nations that permit non-prescription access to potent anticholinergic sedatives, antiemetics, and antispasmodics document considerably higher rates of accidental toxicity compared to jurisdictions enforcing strict prescription mandates.
13. Criticisms, Debates & Limitations
Despite well-established clinical consensus regarding anticholinergic syndrome, several diagnostic and therapeutic controversies remain contentious within emergency medicine and clinical pharmacology:
A primary debate concerns the routine employment of physostigmine versus conservative supportive sedation using benzodiazepines. Skeptics argue that because anticholinergic toxicity is inherently self-limiting as the offending xenobiotic undergoes hepatic biotransformation and renal excretion, aggressive benzodiazepine sedation represents an adequate, low-risk approach that avoids the parasympathomimetic perils of physostigmine (e.g., severe bradycardia, bronchospasm, and seizures). Proponents counter that benzodiazepines fail to restore cognitive clarity, prolong delirium duration, increase aspiration risks, and cause unnecessary critical care admissions that could be averted by rapid reversal.
Another diagnostic challenge involves the unreliability of classic clinical mnemonics. In real-world emergency settings, patients rarely manifest the complete spectrum of classical signs. For example, mydriasis may be absent in up to 15% of confirmed anticholinergic overdoses, or blunted by co-ingestion of miosis-inducing agents such as opioids or clonidine. Relying strictly on canonical features can delay diagnosis. Furthermore, assigning distinct thresholds to the “anticholinergic burden” concept remains problematic; variations among competing risk scales generate conflicting clinical categorizations for identical medication regimens.
14. Related Terms & Distinctions
Differential diagnosis is the cornerstone of emergency toxicology. Several hyperadrenergic and hyperthermic toxidromes closely mimic anticholinergic syndrome, requiring prompt differentiation:
- Sympathomimetic Toxidrome: Induced by cocaine, amphetamines, cathinones, or decongestants. Both conditions share severe tachycardia, hypertension, mydriasis, and agitation. The primary distinguishing clinical physical finding is the state of the skin: anticholinergic syndrome produces completely dry, anhidrotic skin, whereas sympathomimetic excess produces profuse diaphoresis with hyperactive bowel sounds.
- Serotonin Syndrome: Precipitated by serotonergic pharmacotherapy (SSRIs, SNRIs, MAOIs). While both syndromes exhibit altered mental status, hyperthermia, and autonomic arousal, serotonin syndrome is distinguished by neuromuscular excitation, including spontaneous or inducible clonus, hyperreflexia (most pronounced in the lower extremities), tremor, and diaphoresis, contrasted with the hyporeflexia, choreoathetosis, and dry skin of anticholinergic toxicity.
- Neuroleptic Malignant Syndrome (NMS): An idiosyncratic dopamine receptor antagonism reaction characterized by hyperthermia, autonomic instability, and delirium. NMS is distinguished by generalized, profound “lead-pipe” muscle rigidity, elevated serum creatine kinase, diaphoresis, and a comparatively indolent onset over several days, unlike the sudden onset and loose motor floccillation of anticholinergic syndrome.
- Cholinergic Syndrome: The absolute physiological antithesis of anticholinergic syndrome, caused by organophosphates, carbamates, or nerve agents. Rather than dryness and urinary retention, it produces uncontrollable body-wide hypersecretion summarized by the mnemonic SLUDGE (Salivation, Lacrimation, Urination, Defecation, Gastrointestinal upset, Emesis).
15. Summary / Key Takeaways
Anticholinergic syndrome represents an acute dysautonomic and encephalopathic state induced by competitive blockade of muscarinic acetylcholine receptors throughout peripheral and central tissues. Driven by common pharmaceuticals (antihistamines, antidepressants, antipsychotics, antispasmodics) or ethnobotanical solanaceous plants, its recognition hinges on recognizing the combination of peripheral parasympathetic failure (sinus tachycardia, non-reactive mydriasis, warm anhidrotic skin, urinary retention, absent bowel sounds) and central cholinergic exhaustion (hyperactive delirium, visual hallucinations, purposeless picking behaviors).
Management relies on aggressive supportive resuscitation, evaporative hyperthermia cooling, bladder decompression, and benzodiazepines for psychomotor agitation. In cases of pure anticholinergic poisoning characterized by severe delirium or life-threatening dysautonomia without cardiac conduction anomalies, the centrally active acetylcholinesterase inhibitor physostigmine remains the antidote of choice. In outpatient and chronic care realms, systematic vigilance toward drug-induced anticholinergic burden is essential to prevent iatrogenic cognitive decline and preserve neurological well-being across vulnerable populations.
References
- Burns, M. J., Linden, C. H., Graudins, A., Brown, R. M., & Fletcher, K. E. (2000). A comparison of physostigmine and benzodiazepines for the treatment of anticholinergic poisoning. Annals of Emergency Medicine, 35(4), 374–381. https://doi.org/10.1016/S0196-0644(00)70057-6
- Dawson, A. H., & Buckley, N. A. (2016). Pharmacological management of anticholinergic delirium—theory, evidence and practice. British Journal of Clinical Pharmacology, 81(3), 516–524. https://doi.org/10.1111/bcp.12839
- Gray, S. L., Anderson, M. L., Dublin, S., Hanlon, J. T., Hubbard, R., Walker, R., Yu, O., Crane, P. K., & Larson, E. B. (2015). Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study. JAMA Internal Medicine, 175(3), 401–407. https://doi.org/10.1001/jamainternmed.2014.7740
- Suchard, J. R. (2014). Assessing physostigmine’s contraindication in tricyclic antidepressant ingestions: a review of the literature. Journal of Medical Toxicology, 10(1), 52–60. https://doi.org/10.1007/s13181-013-0348-1