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Anticholinergic Toxicity Medication

  • Author: Mityanand Ramnarine, MD, FACEP; Chief Editor: Asim Tarabar, MD  more...
Updated: Aug 09, 2015

Medication Summary

Medical therapy consists of anticonvulsants, antitachydysrhythmics, sodium bicarbonate, physostigmine, and sedatives.


GI decontaminant

Class Summary

Empirically used to minimize systemic absorption of the toxin.

Activated charcoal (Liqui-Char)


Most useful if administered within 4 h of ingestion. Repeat doses may be used, especially with ingestion of sustained release agents. Limited outcome studies exist, especially when administration is more than 1 h of ingestion.

Administration of charcoal by itself (in aqueous solution), as opposed to coadministration with a cathartic is becoming the current practice standard; this is because studies have not shown benefit from cathartics and, while most drugs and toxins are absorbed within 30-90 min, laxatives take hours to work. Also, dangerous fluid and electrolyte shifts have occurred when cathartics are used in small children.

When ingested dose is known, charcoal may be given at 10 times ingested dose of agent over 1 or 2 doses.


Benzodiazepines and other sedatives

Class Summary

For patients with agitation or psychosis, verbal reassurance and a quiet dimly lit room may be effective. When pharmacological intervention is required, control of agitation may be achieved with the administration of physostigmine or benzodiazepines (DOC). Treat seizures initially with benzodiazepines.

Diazepam (Valium)


Depresses all levels of CNS (eg, limbic and reticular formation), possibly by increasing activity of GABA.

Lorazepam (Ativan)


Sedative hypnotic with short onset of effects and relatively long half-life.

By increasing the action of GABA, which is a major inhibitory neurotransmitter in the brain, may depress all levels of CNS, including limbic and reticular formation.

Monitoring patient's blood pressure after administering dose is important. Adjust prn.

Phenobarbital (Luminal)


Used for patients refractory to diazepam or lorazepam.

Midazolam (Versed)


Used as alternative in termination of refractory status epilepticus. Because water soluble, takes approximately 3 times longer than diazepam to peak EEG effects. Thus, clinician must wait 2-3 min to fully evaluate sedative effects before initiating procedure or repeating dose. Has twice the affinity for benzodiazepine receptors than diazepam. May be administered IM if unable to obtain vascular access.


Cardiovascular agents

Class Summary

Used only when patient is diagnosed with tricyclic antidepressant overdose or when evidence of sodium channel blockade is present. Routine use is not recommended.

Sodium bicarbonate


Anecdotally, has been effective in treating antihistamine induced QRS prolongation (>100 ms) with a quinidinelike ECG pattern.


Cholinergic agents

Class Summary

Reversible anticholinesterase inhibitor that increases the concentration of ACh at the sites of cholinergic neurotransmission. Readily crosses the blood-brain barrier to produce desired CNS effects.

Physostigmine (Antilirium)


Inhibits destruction of acetylcholine by acetylcholinesterase, which facilitates transmission of impulses across myoneural junction.

Clinical effects last 20-60 min. Repeat prn.

Contributor Information and Disclosures

Mityanand Ramnarine, MD, FACEP Assistant Professor of Emergency Medicine, Program Director, Emergency/Internal Medicine/Critical Care, Hofstra Northwell School of Medicine at Hofstra University; Attending Physician, Department of Emergency Medicine, Long Island Jewish Medical Center

Mityanand Ramnarine, MD, FACEP is a member of the following medical societies: Alpha Omega Alpha, American College of Emergency Physicians, American College of Physicians, American Medical Association

Disclosure: Nothing to disclose.


Danish A Ahmad, MD Resident Physician, Departments of Emergency Medicine and Internal Medicine, Long Island Jewish Medical Center

Disclosure: Nothing to disclose.

Specialty Editor Board

John T VanDeVoort, PharmD Regional Director of Pharmacy, Sacred Heart and St Joseph's Hospitals

John T VanDeVoort, PharmD is a member of the following medical societies: American Society of Health-System Pharmacists

Disclosure: Nothing to disclose.

Michael J Burns, MD Instructor, Department of Emergency Medicine, Harvard University Medical School, Beth Israel Deaconess Medical Center

Michael J Burns, MD is a member of the following medical societies: American Academy of Clinical Toxicology, American College of Emergency Physicians, American College of Medical Toxicology, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Asim Tarabar, MD Assistant Professor, Director, Medical Toxicology, Department of Emergency Medicine, Yale University School of Medicine; Consulting Staff, Department of Emergency Medicine, Yale-New Haven Hospital

Disclosure: Nothing to disclose.

Additional Contributors

David C Lee, MD Research Director, Department of Emergency Medicine, Associate Professor, North Shore University Hospital and New York University Medical School

David C Lee, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Medical Toxicology, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

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