ICU Decoded › Library › Ward Pathways › Emergency / Toxicology › Tricyclic Antidepressant OverdoseTricyclic Antidepressant OverdoseICU / resuscitation
Emergency / Toxicology · Ward Pathways · Locked — free with a referral
By Dr Javed Akhtar · Last reviewed 2 October 2026
Presentation Took 30 tablets of amitriptyline 2 h ago; drowsy, dry, flushed, pupils dilated; HR 128, BP 88/50; QRS 128 ms
Red flags QRS widening Arrhythmia Seizures Hypotension GCS falling Differential diagnosis Other sodium-channel blockers (antihistamines, carbamazepine, cocaine) Anticholinergic toxidrome Serotonin syndrome Hyperkalaemia When to admit, call ICU or discharge Admit: All symptomatic or significant ingestions (>5 mg/kg amitriptyline equivalent)ICU: QRS >100 ms, arrhythmia, seizures, hypotension, GCS ≤8Intubate: GCS ≤8, seizures, hypoventilationVasopressors: Hypotension after fluids and bicarbonate — noradrenalineKey points QRS >100 ms predicts seizures; >160 ms predicts ventricular arrhythmia. Sodium loading plus alkalinisation reverses sodium-channel blockade — hypertonic saline if bicarbonate fails. Always check paracetamol — co-ingestion is common. Never Give flumazenil (seizures) Use physostigmine, class IA/IC antiarrhythmics or phenytoin Withhold intubation for fear of arrhythmia Give charcoal to a patient who cannot protect the airway Common mistakes Flumazenil Late bicarbonate Charcoal with an unprotected airway Missing co-ingestion Disposition and follow-up ICU until ECG normal; psychiatric assessment before discharge.
Locked ABCDE first moves The step-by-step decision sequence Order set Monitoring timeline and escalation triggers Treatment doses and preparation Discharge package Open the full pathway in Ward Pathways
Free with a referral from any ICU Decoded member, or by applying with your medical registration. How access works .
← Dengue with Warning Signs · Paracetamol Overdose →
More Emergency / Toxicology pathways
Part of Emergency / Toxicology in Ward Pathways — open the interactive version .