Anticholinergics toxidromes

Chronic ingestion of greater than therapeutic amounts of atropine may produce symptoms of the anticholinergic toxidrome. 

Symptoms may begin within 1-4 h after ingestion. Jimson weed causes the anticholinergic toxidrome characterized by tachycardia, mydriasis, dry flushed skin, decreased bowel sounds, urinary retention, sedation, and hallucinations. Symptom resolution may vary from 1 day to 2 weeks. 

Cyclobenzaprine, a tricyclic amine structurally very similar to amitriptyline (see Figure 34-10), is used as a centrally acting skeletal muscle relaxant. Like amitriptyline, cyclobenzaprine causes sedation, produces central and peripheral muscarinic blockade, and potentiates adrenergic actions. In overdose, cyclobenzaprine may cause a typical anticholinergic toxidrome and cardiac arrhythmias, hypotension, and coma. However, cyclobenzaprine overdose is not as frequent nor as lethal as amitriptyline overdose. 

Toxic syndromes ( toxidromes ) are clinical syndromes that are essential for the successful recognition of poisoning patterns. A toxidrome is the constellation of clinical signs and symptoms that suggests a specific class of poisoning. The most important toxidromes are (1) anticholinergic, (2) cholinergic, (3) opioid and opioid withdrawal, (4) sedative-hypnotic and sedative-hypnotic withdrawal, and (5) sympathomimetic. Symptoms for these toxidromes are listed in Table 34-2. 

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