History and exam
Key diagnostic factors
common
presence of risk factors
Risk factors include: history of depression, obsessive-compulsive disorder, chronic pain, attention deficit hyperactivity disorders.
change in mental status
If a patient has reduced consciousness, monitor for respiratory depression as intubation may be necessary.[11]
tachycardia
Sinus tachycardia is the most common rhythm in tricyclic antidepressant overdose. Wide complex tachycardia occurs in severe overdose. Its absence makes the diagnosis of severe poisoning unlikely.
hypotension
As a result of alpha-1 antagonism, hypotension is quite common.[4]
mydriasis
Dilated pupils are part of the anticholinergic toxidrome.
Do not use physostigmine to reverse anticholinergic signs caused by tricyclic antidepressant overdose because, in rare cases, it has been associated with causing asystole.[20]
Absence of anticholinergic toxidrome makes the diagnosis unlikely, although cardiovascular effects can be so prominent that these anticholinergic manifestations may be overlooked.
warm, dry, flushed skin
Part of the anticholinergic toxidrome.
Do not use physostigmine to reverse anticholinergic signs caused by tricyclic antidepressant overdose because, in rare cases, it has been associated with causing asystole.[20]
Absence of anticholinergic toxidrome makes the diagnosis unlikely, although cardiovascular effects can be so prominent that these anticholinergic manifestations may be overlooked.
change in mental status
Changes in mental status, varying from slight drowsiness to delirium or coma, are part of the anticholinergic toxidrome.
Do not use physostigmine to reverse anticholinergic signs caused by tricyclic antidepressant overdose because, in rare cases, it has been associated with causing asystole.[20]
Absence of anticholinergic toxidrome makes the diagnosis unlikely, although cardiovascular effects can be so prominent that these anticholinergic manifestations may be overlooked.
decreased or absent bowel sounds
Part of the anticholinergic toxidrome.
Do not use physostigmine to reverse anticholinergic signs caused by tricyclic antidepressant overdose because, in rare cases, it has been associated with causing asystole.[20]
Absence of anticholinergic toxidrome makes the diagnosis unlikely, although cardiovascular effects can be so prominent that these anticholinergic manifestations may be overlooked.
urinary retention
Part of the anticholinergic toxidrome.
Do not use physostigmine to reverse anticholinergic signs caused by tricyclic antidepressant overdose because, in rare cases, it has been associated with causing asystole.[20]
Absence of anticholinergic toxidrome makes the diagnosis unlikely, although cardiovascular effects can be so prominent that these anticholinergic manifestations may be overlooked.
ophthalmic signs
Divergent squint, internuclear ophthalmoplegia and gaze paralysis; nystagmus may also be seen.
neurological signs
Ataxia, and myoclonic and choreoathetoid movements, may be seen. Increased muscle tone, hyperreflexia, and extensor plantar responses may occur.
Other diagnostic factors
common
features of serotonin syndrome
The clinical features of serotonin syndrome include hyperpyrexia, impaired consciousness level or agitation, increased muscle tone, and clonus. It is often associated with an elevated creatine kinase level.[13] Features of serotonin toxicity may also occur if the patient has co-ingested other drugs that increase the effect of serotonin, or is taking one of these drugs therapeutically. These include: selective serotonin reuptake inhibitors, venlafaxine, monoamine oxidase inhibitors, amfetamines, cocaine, MDMA (ecstasy), linezolid, tramadol, or triptans.
Risk factors
strong
history of depression
obsessive-compulsive disorder
May lead to tricyclic antidepressant (TCA) overdose. Risk of overdose is related to the use of TCAs prescribed for the disease, rather than the underlying disease itself.
chronic pain
May lead to tricyclic antidepressant (TCA) overdose. Risk of overdose is related to the use of TCAs prescribed for the disease, rather than the underlying disease itself.
attention deficit hyperactivity disorders
May lead to tricyclic antidepressant (TCA) overdose. Risk of overdose is related to the use of TCAs prescribed for the disease, rather than the underlying disease itself.
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