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Poisonings - Acute Guidelines for Initial Management Poisonings - Antihistamines / antihistamine-decongestant poisoning Poisonings - Tricyclic antidepressant poisoning
For 24 hour advice, contact the Victorian Poisons Information Centre on 13 11 26
Anticholinergic syndrome results from competitive antagonism of acetylcholine at central and peripheral muscarinic receptors. Central inhibition leads to an agitated (hyperactive) delirium - typically including confusion, restlessness and picking at imaginary objects - which characterises this
toxidrome. Peripheral inhibition is variable - but the symptoms may include: hot, dry skin, flushed appearance, mydriasis, tachycardia, decreased bowel sounds and urinary retention. There is a spectrum of severity ranging from mild symptoms to a life-threatening condition - although seizures, coma and
cardiovascular toxicity may not be mediated by muscarinic effects, rather secondary to drug effects at other receptors, as many anticholinergic medications are active at numerous receptors / ion channels. Polypharmacy overdoses may make the anticholinergic toxidrome less apparent.
If anticholinergic syndrome is suspected please
seek senior advice and discuss with toxicologist.
Anticholinergic syndrome may occur following:
Atropine is the prototypical anticholinergic (anti-muscarinic) drug
Figure 1: Examples of Angel’s Trumpet
Diagnosis is based on a history of ingestion/exposure to one or more anticholinergic agents and the presence of characteristic symptoms and physical signs.
The characteristic feature of toxicity at central receptors is agitated delirium. This may include:
Other central signs include tremor, coma, increased tone, and seizures (rare).
The features of toxicity at peripheral and central receptors can be remembered using the following mnemonic
The severity of symptoms and signs is generally dose dependent.
Mydriasis and blurred vision
Dry mouth and skin
CNS depression / coma
Cardiac conduction abnormalities (QRS widening and increased QT interval)
Circulatory collapse / hypotension
The differential diagnosis to consider in cases of suspected anticholinergic syndrome includes:
Children requiring care beyond the comfort level of the current hospital
For emergency advice and paediatric or neonatal ICU transfers, call the Paediatric Infant Perinatal Emergency Retrieval (PIPER) Service: 1300 137 650.
Accidental ingestion: Parent information sheet from Victorian Poisons Information centre on the prevention of poisoning
Intentional self-harm: Referral to local mental health services e.g. Orygen Youth Health: 1800 888
Recreational poisoning: Referral to YoDAA, Victoria's Youth Drug and Alcohol Advice service: 1800 458 685
Information Specific to RCH/ MMC
All patients with intentional ingestions, should be admitted under the adolescent or psychiatric units
Last updated August 2017