Anticholinergic Toxicity

Anticholinergic compounds oppose the action of the endogenous neurotransmitter acetylcholine at its target receptors and are found in over-the-counter and prescription medication, natural products, and plants. Anticholinergic medications, such as atropine and scopolamine, are used for the treatment of a wide range of conditions, including bradycardia, motion sickness, and insomnia. Antihistaminergic medications, such as diphenhydramine, also possess anticholinergic activity and are used in the treatment of seasonal allergies, common cold symptoms, and allergic reactions. Other medications, such as antidepressants (especially the older tricyclic class), antipsychotics, muscle relaxants, and anticonvulsants, can act as anticholinergic agents or produce anticholinergic side effects. Toxicity can result from therapeutic misadventure, intentional overdose, recreational use, and pediatric exposures. This review covers the principles of toxicity, immediate stabilization, diagnosis and definitive therapy, and disposition and outcomes. Figures show the anticholinergic toxidrome, look-alike structures, and electrocardiographic changes in tricyclic antidepressant overdose. Tables list medicat